When comparing GNU/FreeBSD vs FreeBSD, the Slant community recommends FreeBSD for most people. In the question“What are the best server OSes?” FreeBSD is ranked 3rd while GNU/FreeBSD is ranked 9th. The most important reason people chose FreeBSD is:
Ports provide a wide collection of software which are easy to build, install and modify. They contain recipes and patches to build various software, so you can simply run "make && make install" to build and install the software. You may also keep local patches and it would be picked up automatically. It also allows you to use the latest software even if you are not using the latest version of the operating system.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Not tied to systemd
Pro Very customizable
It's more barebones than Linux so you can customize it every way you like.
Pro Clean design
Clang toolchain has a cleaner design than gcc, it's easier to implement a front-end to LLVM.
Pro Powerful ports collection
Ports provide a wide collection of software which are easy to build, install and modify. They contain recipes and patches to build various software, so you can simply run "make && make install" to build and install the software. You may also keep local patches and it would be picked up automatically. It also allows you to use the latest software even if you are not using the latest version of the operating system.
Pro Batteries included
Base system contains basic developer tools, including compiler, debugger and system utilities.
Pro Jails mechanism
Jails allow for partitioning a system into several independent "mini-systems", a feature not found in many of the popular OS choices.
Pro Stable updates
Pro Great philosophy
FreeBSD won't change everything from a version to another, it tries to keep and maintain old tools as long as possible, and won't replace half the system every two versions like GNU/Linux distributions such as Ubuntu, Arch or Fedora does. everything is stable and also pretty minimal. FreeBSD is designed for performance.
Cons
Con Linux can do pretty much everything it can, and better
Unless you're looking for some niche server functionality, it's pretty much certain that a linux distro already has whatever you want in a more efficient and easier to use form.
Con Server-oriented, good for developing back-end software and not much else
Con No systemd
Systemd makes it trivial to automatically start and manage programs, offering a whole lot more control than a cobbled together bundle of some archaic init system, cron and random bash scripts.
Con Pathetic third-party application support
Need to run Photoshop? No luck. Even most software that's portable to Linux will have a hard time running on FreeBSD. You're stuck with ONLY running the free software.
Con Inferior driver support for workstations
Lack of drivers for some modern personal devices.
Con Not for beginners
If a user needs an easy way to navigate around the filesystem, a text only Unix-derivative is not his best choice.