When the KDE 4 rewrite first released version 4.0, it was not very polished and even had a bunch of features missing. 4.1 was better, but still not enough to satisfy reviewers (although actual users liked it somewhat better). By release 4.4, it was back to being polished and pretty complete, but everyone had stopped paying attention after a few "bad" (according to reviewers, if not actual users) versions.

Fedora has a KDE spin and I've been using it for something under a year. The reason I chose KDE over gnome was that I could configure things. Gnome2 (and even 3) has almost no configuration (accessible to user via the UI at least). It's almost like Chrome.

But it's still nowhere close to perfect or even fine. It's broken in many places. But it might be Fedora's fault, didn't try it on any other distro.