This distro, based on the Ubuntu LTS with a custom desktop environment called Pantheon, is a turnkey OS with a focus on user experience design.
Ranked in these QuestionsQuestion Ranking
Pro Extremely user-friendly
This distribution promises you a very tailored user experience and it does deliver on that promise. The developers provide you with a custom desktop environment and a set of neat programs. And the whole desktop looks simply gorgeous.
Pro UI design consistency
Excellent uniformity between all the stock application and an overall extremely clean design with simple animations.
Pro Lightweight & fast
Runs well on limited-resources hardware, including netbooks or chromebooks.
Pro Built on Ubuntu
Built on Ubuntu LTS with all its qualities and support.
Pro Simplicity, limited configurability
Sane defaults with less confusion for new users.
Pro Active Google+ community
There is a place where elementary users can ask their questions and usually get answers pretty quickly. Not only by the other users, but the devs are pretty active themselves, often engaging in the discussions on the hows, whys and plans of the os.
Pro Consistent development practices
All Elementary apps are written in Vala and hosted on Launchpad, and there are standard APIs such as contractor for applications to interact with one another. This is different from most distros, in which apps are written in a variety of languages. This design decision makes it easy to get started developing for Elementary and to understand how the various pieces fit together.
Pro A dedicated StackExchange site
elementary OS has a dedicated StackExchange site where users can easily find answers to common questions.
Pro With new tweak tools customisation is not a problem
Now the OS is amazingly customisable
Pro If you like MacOSX the UI/UX is similar
Con Old base and applications
The slow release schedule makes the applications outdated. It drags behind Ubuntu LTS (on which it's based) which itself drags behind Ubuntu which is often still quite far behind Arch for example.
Con Very slow development cycle
elementary does not offer any release date for their stable releases going more with a "it's done when it's done" attitude. Making depending on newer apps a difficulty as well as a poor choice for those that need consistent release schedules for their OS.
Con Poor Linux community reputation
The devs of elementary OS feel anyone not paying for their Ubuntu respin are not worthy of using it. Which upset a good bit of people. Obviously the core dev team have issues with their community outreach and PR.
Con Window control button placement may be unintuitive to some
elementary OS has window controls on the left side of the window. It may be less intuitive to users coming from other operating systems that put window controls on the right.
Con Emacs doesn't work
Emacs crashes due to a partial gnome library update.
Con Outdated or bad default applications
Con Boring UI
It can be very boring.