When comparing Debian GNU/Linux vs macOS, the Slant community recommends Debian GNU/Linux for most people. In the question“What is the best laptop OS?” Debian GNU/Linux is ranked 16th while macOS is ranked 25th. The most important reason people chose Debian GNU/Linux is:
Debian offers stable and testing CD images specifically built for GNOME (the default), KDE Plasma Workspaces, Xfce and LXDE. Less common window managers such as Enlightenment, Openbox, Fluxbox, GNUstep, IceWM, Window Maker and others can also be installed.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Wide choice in desktop environments
Debian offers stable and testing CD images specifically built for GNOME (the default), KDE Plasma Workspaces, Xfce and LXDE. Less common window managers such as Enlightenment, Openbox, Fluxbox, GNUstep, IceWM, Window Maker and others can also be installed.
Pro Standard vanilla Linux desktop
Debian runs standard Gnome, XFCE, KDE - it doesn't use its own special desktop environment or debian specific modifications or customisations, which means that users benefit from the work of the whole Linux community, Debian developers can focus on the distribution itself, and any support for your desktop environment on other distributions should work on Debian as well.
Pro Wide choice of hardware platforms
Debian has the widest choice of hardware platforms, including:
amd64, armel, armhf, i386, ia64, kfreebsd-i386, kfreebsd-amd64, mips, mipsel, powerpc, sparc, s390, s390x, source, multi-arch.
Pro Very stable
Debian has a Stable branch, where packages are thoroughly tested before release. Furthermore Debian is know to be the definition of stable when it comes to production systems.
Pro Install and forget
Once installed you can almost forget about it and start to use your desktop for your daily tasks.
Pro Easy to find help with any problem
Debian is one of the oldest and most popular distros out there. Debian's popularity means that you will always be able to find a solution for your problem just by searching on Google, or if by chance nobody has had the problem you are having it's very easy to ask the community and quickly get a solution.
Pro Comes with over 55.500 packages
Because of its popularity, Debian has a lot of applications available which range from productivity programs to business software, games and development tools. It comes with over 55.500 packages (software that is precompiled and ready to be installed on a local machine) -- all of them for free.
Pro Highly secure system
Known for being consistent in maintaining a highly secure system. Several other popular distros use Debian as a base or core for their own Linux OS, the security being one of the main factors why it's so commonly used.
Pro Rolling or Release based
Every Debian Release can either use a Rolling or Release based model.
Pro Well-working team
The developer works very well so the the code is one of the best written out there.
Pro A lot of ways to install software
You can either use aptitude, apt or apt-build to install software from the Debian package archives.
Pro Great for gaming
As Debian is the base for SteamOS and because Ubuntu is based on it, it's almost certain that all Linux games will run properly and require no hacks like creating symbolic links because of some hardcoded paths.
Pro Big open-source project
The Debian project is one of the biggest open source projects with over 5000 active contributors.
Pro Supports SecureBoot
You don't have to disable SecureBoot if you use it, which is useful for LiveUSB or dualboot setups.
Pro The Debian Social Contract
Guaranteed commitment to adherence to values, principles, priorities, requirements and guidelines by the Debian project.
Pro A real installer
Unlike other distributions that just extract their Live image, Debian offers a real traditional and modular installer to customize the installation.
Pro Strict separation of non-free software
Debian is one of the few distros that let the user choose if he wants a free system or not.
Pro Debconf
Depending how it is configured debconf does the most of the hard work for you and only asks you with configuration /file conflicts.
Pro Widely supported
Almost any software that is available for Linux provides a Debian package.
Pro Many ports
Debian supports almost any Kernel maintained CPU instructions set. It has also a few non Linux Ports.
Pro Apt-build
It is possible to rebuild the entire system and optimize it for your hardware (of course, it is not as detailed as Gentoo's USE flags).
Pro Unique release cycle
The most Linux distros have one or two stages before a release, but Debian has five before a new stable version is released (experimental > unstable > testing > code-freeze/bug hunting > stable).
Pro TUI installer
The Debian installer can still be launched as text/curses-like installer which is more compatible and keyboard-friendly than the graphical version.
Pro Standard archives
Debs are normal ar and tar archives with shell scripting and additional gz, bz, lzma or xz compression.
Pro Live install images for CDs, DVDs and USB thumb drives
Debian releases live install images for CDs, DVDs and USB thumb drives, for the i386 and amd64 architectures, and with a choice of desktop environments. These Debian Live images allow the user to boot from a removable media and run Debian without affecting the contents of their computer.
Pro Wise release model
Debian stable does not update a lot and instead provides stability and well tested softwares. You don't get distracted by every shiny new stuff that comes out, and focus on what matters: productivity and reliability of your system.
Pro Debian Fast Track for stable
Stable gets backported software from here.
Pro Great choice for returning Linux users
If you haven't used Linux for a long time, say 5-10 years, it's a great distro in which you can quickly get in the boat again. You don't have to worry about falling back. Everything is in its place.
Pro Has small amount of today's bugs (e.g. no duplicate web cameras in Skype - likely not Skype's fault)
But has quite a few bugs from 2016-2017, apparently for long term.
Pro Polished UI
The UI of Mac OS is rather unrivaled. The smooth, responsive, and cohesive UI makes the system quite joyous to use.
Pro Easy access to lots of great dev tools
There's a large selection of great development tools available for OSX. The operating system itself comes bundled with a powerful terminal emulator, called Terminal. Additionally, Apple provides tools, like Xcode, an IDE that contains a comprehensive collection of tools for developing OSX and iOS software, for free.
Pro Based on Unix
macOS being a UNIX certified system means that you can install a lot more stuff with a lot fewer headaches than if you were on Windows.
Pro Powerful terminal
It's very similar to a Linux terminal.
Pro Best support for Objective-C
Pro More commercial software and gaming support compared to other Unix systems
Adobe CC, MS Office, Steam games.
Pro Has many special tools for developers
Has support for multiple IDEs.
Pro Lots of open-source software available
Because it's Unix under the fancy GUI, most open source ports easily to it.
Pro Ideal setup, out of the box
Next to no custom configuration is necessary.
Pro Great Git GUI tools
Tower, Kaleidoscope, SourceTree.
Pro Has software that only runs on Mac
For example, Sketch.
Pro Streamlined workflow between devices
Because this is an Apple product, there is a streamlined workflow between your computer and all mobile devices. For example, if you type an a Pages document, once you save, you can open the updated document just moments later on your iPad, and vice versa. The same goes for iMessage, (yes, you can text people with your phone number from your computer. Actually, you can text other people with apple devices with just your Apple ID, with or without a phone number, for free!) Numbers, Notes, Reminders, Contacts, and just about any other Apple workflow application.
Pro Great modifier key layout
Pro Using VMware you can also run Windows 10 on the Mac
This is useful for testing and some development tools that are Windows-only (XML Spy, MapForce).
Pro You need it to compile macOS or iOS apps
Cons
Con Stable release contains extremely outdated packages
If you want the newest packages, you'll have to do a minimal installation of Debian stable then upgrade to testing or you need to install testing directly.
Con No default support for unfree drivers
Debian does not official support unfree software so if you have a wifi card or anything elese that requires an unfree driver you will need to download the unofficial/non-advertised non-free iso image which contains all unfree driver packages.
Con Ridiculous package splitting
Even though it makes sense to split devel and the actual binary of an application, the splitting has become as mess in debian and its derivates: for example the nvidia driver is splitted into over 40 different packages.
Con Internal quarrels harm the project
Instead of working all together to provide the best Operating System, some maintainers are just ignorant and aggressive to new ideas or new maintainers. That led to many crises and controversy in Debian's history.
Con Systemd is everywhere
Systemd is very hard to debug by itself, and can break in very strange ways (such as not being able to mount a single partition on bootup), but the increasing number of desktops that are relying on specific functionality provided only by systemd (policy kit, dbus, etc) makes the entire system more fragile and harder to debug.
Con Outdated kernel of the live system
Since the LiveCD is based on Debian stable the kernel is old, outdated but stable.
Con Not designed for general desktop usage
By default, Debian Stable is not that great of a distro for general desktop usage, since the packages are very outdated. You'll have to spend a while configuring the system in order to make it work.
Con No choices
Debian basically doesn't give you any choices, even dpkg supports this feature with virtual packages: for example, it is very hard to use a different sound system than ALSA, like OSS4 or to use ALSA with pulse audio emulation, and the same goes for different init systems.
Con Inconsistent init systems
While Linux uses systemd, non-Linux ports use the traditional sysvinit.
Con Hard to learn
Con Breaks if you suspend/resume
Breaks when you resume the activity on the system if you use nvidia cards.
Con Buggy and non-user friendly
You need to know almost as much as Arch and deal with documentation not as good as the Arch wiki in order for Debian to work.
Con No good choices of fresh desktop environments
GNOME is quite outdated and buggy;
KDE is too old, even in Sid it is at 5.14 branch (at Jun 13 2019 Plasma 5.16 is available in many rolling/fresh distros);
XFCE behaves like crooked, visual artifacts at the taskbar and so on;
Cinnamon as far as I know works better in Linux Mint compared to (almost) any other distro;
For other desktop environments (e.g. MATE) can't say - these are too new (as projects) and possibly incomplete, thus might have many bugs.
Con Old software is not useful, but is stable
Certainly for the stable and old stable versions. But the testing version has quite up to date software.
Con Expensive
OSX is tied Apple hardware and Apple hardware tends to be expensive for what it gives.
Con Limited hardware
Usually, the hardware that can run this can't be upgraded.

Con Most software is closed source
For people who like to use open source tools for their development work, this may be a problem. There's plenty of advantages to open source software, one of which is the ability to tinker with and customize the tools themselves that you are using. Although there's plenty of FOSS tools available for Mac, especially through Homebrew, the number of packages available is much lower than the number of packages available for any Linux distribution.
Con Closed source
Mac OS is closed source itself, which means that it is developed more slowly and has more problems.

Con No native package management
A comparison of package managers available for OSX can be found here.
Con Poor application support
Fewer apps run on Mac OS than on Windows or Linux.
Con Bash version is obsolete
macOS comes with an obsolete version of Bash, due to licensing issues.
Con Vendor-Lock-in
You are now forced to use the Apple services.
Con Silly modifier keys layout
The Command key is strange, Alt is where Super should be.
Con Poor X11 integration
The most open source software does work but is very poorly integrated due apples ancient version of the X-server.

Con Very few options for running hosted, on the cloud
Con Too little customization options
Con Touchbar on Macbook Pro's
Con Not very user-friendly
