Lately I have been working more and more on my Mandriva 2010 and Fedora 12 KDE desktops. Both of them are KDE4.3.3 and both of them rock hard in my opinion.
Back in the day when I started using KDE, it was KDE4 that got my attention. I never used KDE 3.5, though I have read that it was great. Anyways, when I started using KDE4, it felt bloated, resource eating, and buggy. Plasma was still not mature enough, many of the widgets didn´t work as expected, the menu tray was simply terrible, and it was frequent to see applications crash or behave unexpectedly. Needless to say, I stuck to Ubuntu and its awesome GNOME implementation. Under GNOME, everything felt right and doing what it was supposed to do, and with the right settings, it looked even better than KDE4 in my oppinion.
Now, come October and Mandriva and Fedora go live with their 2010 and Constantine releases, both of which sporting KDE 4.3.2, which I quickly upgraded into 4.3.3. I must say that I was blown away. The KDE desktop has improved a lot in a short time. It feels very responsive and light now. Most widgets work great and look awesome, and applications are as solid as their GNOME counterparts. Compiz effects even perform better and feel smoother under KDE 4.3.3 than they do under GNOME 2.26 (comparison run under the same hardware). On top of that, monitoring resource management does not really give any significant edge to GNOME, as used to be the case. Both desktops are now optimised and, while obviously heavier than XFCE and other lighter desktop implementations, they perfectly balance performance with functionality.
I still think that GNOME may have a slight edge when starting certain applications. Especially the latest Ubuntu implementation, Ubuntu 9.10, is lightning fast when opening Open Office. However, I can see a significant drag on both Mandriva and Fedora when opening the same application. That could be down to the GTK libraries, which are native to GNOME, though.
In any case, I wanted to share that I am a lot happier with KDE these days, and that it no longer feels to me like an inferior product when compared to GNOME. Back when I started using KDE, I was faced with issues that got me frustrated, and I always ended up going back to my Ubuntu or Mint desktops. However, I saw lots of potential in KDE and kept trying their new releases.
I am now glad that I did, because I finally feel at home and happy with KDE4.3.3. I no longer feel the need to use any GTK applications (with exception of gnome-system-monitor) and I love my KDE desktops more every day. I am looking forward to enjoying KDE4.3.4 soon, and can´t wait to see what they pull off with KDE4.4.
In addition, judging by the GNOME3 mockups I have seen, It feels like KDE will be a keeper. On the other hand, I hope the GNOME team listen to the community and don´t continue down the suicidal route they have taken. I would definitely like to keep using both KDE and GNOME, but not if GNOME 3 becomes a netbook tipe of desktop!
On the negative side, or maybe on the side I personally don´t like, I must say that KDE still has a lot of work to do when it comes to Kwin themes, color schemes, and control themes.
Kwin themes are all looking terrible, in my opinion. I always end up using Emerald, because there is not a single Kwin theme that looks half decent to me. GNOME window themes are much more abundant, and the average quality is much higher, I think.
Color schemes are also limited under KDE, and their editing tool is not nearly as intuitive as that of GNOME. Finally, there are just a handful control themes, and all look terrible to me. I end up using clearlooks all the time, which is the only one that looks sharp, I think. I don´t understand why there are so few control themes, and why there is no tool enabled to include more, as is the case for many other look and fell features.
All in all, with the exception of these little annoying (and completely subjective) look & feel issues, it is clear to me KDE4 has become an awesome desktop experience, and I very much recommend it!