I used it in a 3 person company and I hated it for many of the reasons stated here. The topic based UX is terrible in practice and the whole thing feels janky and ugly.
Secret: Most game releases, however sturdy and flawless they might seem, are a snapshot of a cardhouse in a storm, momentarily held together by baling wire, gum and worn tufts of the souls of overworked game developers.
There's some debate about it, apparently, but I recently saw articles mentioning that Zynga was valued at $6 bn, while EA's market cap is $5 bn (http://finance.yahoo.com/q?s=ERTS&ql=0).
It was a pretty transformative experience - if that hadn't happened to me back then (while I was scoffing at my friend for missing classes to play EverQuest), I would probably have walked right into the WoW trap :)
I really want to like it…