I'm another one who just recently switched to using KDE and I can now absolutely positively say that KDE is the best computer desktop environment that is available today. Nothing comes close to KDE when it comes to its power and elegance.
I started using KDE three weeks ago because GNOME3 and Unity disappointed me a lot. KDE is very customizable so you can really made the desktop look and work exactly as you wish and you are not limited to one default like with other desktops. I also love the tagging and rating features that are available in KDE applications. Everything in KDE is very well integrated. Not to mention how gorgeous KDE looks. KDE is the perfect desktop and I'm sad I did't try KDE before.
The only problem with kde4 (4.6 in my case) is that it isn't integrated with the underlying linux. For example if you do 'kwrite /etc/fstab' you see tons of errors. And if you follow the recommendation to do 'kdesu kwrite /etc/fstab' it does work unless you're already 'su' in which case it crashes terribly and even dr. konqi dies (so they don't get the error reports).
The solution is to 'export $(dbus-launch)' if and only if HOME is /root, and use xdg-su instead of su OR kdesu, which is apparently incompatible with kde itself???
In any case, I like the concept but it should work with the underlying system rather than trying to take it over. Some of us still have use for gcc.
But as far as the desktops go, there are many options you may easily miss first time through. It ends up being the best of Windows plus the best of NextStep (see WindowMaker if you don't know what NextStep is about), all in one. I love that part.
But read HOME (per above) instead of UID or whatever you're doing in kdesu. That's a mess. And since an app may run in a script, it's kdesu that needs to detect where the user's socket lives -- if you want "user friendly", which seems to be the prime directive of kde.
I've been a long time GNOME user and when GNOME 3 came out I started looking at other desktops and was pleasantly surprised with KDE 4.6. KDE looks much better, and has a lot more cool features. There are also some nice technologies you can't fiond in GNOME (like file tagging, commenting) and I love the runner bur you get with Alt+F2 from which you can do almost everything quickly. Also most of the KDE apps also look better and have much more functionality compared to GNOME equivalents (I'm falling in love with Amarok, K3b, Digikam and Kdenlive).. And apps and desktop are much more smoothly integrated.