The case for Ubuntu on the server
Something I haven't discussed much over the years is Ubuntu's usefulness on servers. The original idea behind Ubuntu was to take Debian, a super-stable distribution that's always had more success on servers than desktops, and polish it up for desktop use, with easier installation and configuration and a quick, regular release cycle.
That Debian heritage still underlies the project, though, and for a few years now Ubuntu has been trying to target the server market as well. I still run Debian on my servers, and the main reason is the release cycle. I don't have any servers that need to be updated every six months, so the LTS releases are the only ones that I'd feel comfortable running.
While you're meant to be able to upgrade directly between LTS releases, skipping all of the six-monthly releases between them, I have to wonder just how much time and effort goes into testing that upgrade path, with the constant time pressures that the developers are under.