I might quibble with the "Linux's command line offers no benefits" line. It's true that the
shell is identical. But OS X, out of the box, is lacking huge chunks of what you expect to find out-of-the-box on a typical Linux distribution. That's a problem for anyone who wants to be able to portable scripts, etc... Add that to the fact that the existing package managers for the command line tools are kinda lacking, and I'd honestly put OS X behind even cygwin as a good example of a OS command line environment.
The bit about Gnome vs. KDE is a sore point, alas. Canonical itself is clearly a Gnome shop, and that's what they ship on their core Ubuntu Desktop distribution. But KDE has a huge user base of near-fanatic volunteers, who insist (how dare they!) on maintaining the Kubuntu distribution in parallel. Both desktops work very well, and at this point neither is likely to disappear.
FWIW, I use Gnome and prefer the architecture and API.