I want to upgrade my Ubuntu Lucid to Kubuntu Maverick (with a fresh install of course). I want to try KDE, but I have heard there are slight issues with the native Qt applications compared to the GTK application equivalents - such as nvidia-settings, Gimp, Ubuntu Software Centre, and especially th eSynaptic package manager (which in detail showed the administration package / KPackageKit is not powerful yet than synaptic)
I believe we can have run GTK+ applications in KDE, but GTK+ applications do not blend with the KDE desktop. Also Java does not provide a GUI for KDE/Qt.
Should I install Kubuntu (KDE/Qt) or stay with ubuntu (GNOME/GTK +)?
Using Ubuntu (Gnome-desktop) or Kubuntu (KDE-desktop) is in the end a choice of preference and maybe what applications you use more.
You can even install both, by making sure that both packages, ubuntu-desktop and kubuntu-desktop are installed. With this setup you can decide when you login, which desktop you want to use (or with the change user option have both desktops running at the same time).
if you want to have a better blend of GTK apps in KDE, you can select the Curve theme for them in the settings (I think it is in appearances in system-settings).
I do not think there is a real objective answer more than this for your question, and we do not want to start any flaming here :)
In addition do txwikinger answer, I can say that Ubuntu is Canonical's flagship product and it is polished more (for example: Software Center, UbuntuOne Client). So I would stick with Ubuntu, but install kubuntu-desktop package and try it yourself :)
I started with Ubuntu 9.10 and moved to Kubuntu 9.10 shortly after. I run both KDE and Gnome apps on Kubuntu with no real issues.
I tried Kubuntu 10.10 last night and decided to go back to Ubuntu for these reasons:
Kubuntu was slightly slower and had more lag. This was probably because it had an easier time detecting the video card and enabling the desktop effects. My Ubuntu install still can use desktop effects even after enabling the NVidia driver. Need to investigate.
The Ubuntu 10.10 startup and shutdown is a lot cleaner looking. With Kunbuntu, during shutdown some messages are thrown to the screen. After installing a ton of Gnome apps, my Kubuntu system wouldn't start the X display any more and locked up on startup. Too unstable for me to continue using.
The WIFI settings on Ubuntu, and the prompt for keyring, is prompted only once on Ubuntu but Kubuntu asks me to enter my password 3 times.... annoying.
Kubuntu had a "Desktop Widget" type of presentation whereas Ubuntu is simple and more elegant/traditional. Kubuntu also had a app menu that looks like Windows7 but I prefer the simpler Win2000 type of menu.
The placement of shutdown button is much better in Ubuntu, at the upper right corner of screen.
I have used Xubuntu for many years and its great (simple but great). For some years I used Ubuntu at work and Xubuntu in my home computer. Now I use Xubuntu at work and Kubuntu in my home computer, why?
I feel that Xubuntu is faster in terms of response and in my job, I want it fast!
Ubuntu is a good choice if you want a balance between performance and beauty.
Kubuntu is (IMHO) more beauty and in general, easier to use and to customize. It comes with a price tag: performance and stability (yea, playing around with widgets may crash your X session, but it is not a big deal). I personally like that in order to add window themes, wallpapers, colors, icons, etc. its as easy as choosing from a list (online) and one click. If you are worry about synaptic, in Maverick you may not even notice any difference while using the Software Center. I personally recommend you to learn "aptitude" instead of synaptic as in my experience it is more useful.
Anyway, don't worry too much about which one to use... install both and try both.
Have fun!
I run a hybrid and everything works great. K3b works fine when I use GNOME and I use the GIMP all of the time in KDE. It does not matter much which you use.
Kwallet manages KDE applications in GNOME and the Gnome keyring manages GNOME applications in Kubuntu. You can use Nautilus in KDE as long as you launch it from the commandline with nautilus --no-desktop, other wise it takes over your desktop with GNOME. You can use Software Centre and Ubuntu One in Kubuntu just fine.
I don't know why anyone would possibly think that Ubuntu is more polished. I agree that it is the flagship but we all know what happens to flagships (Titanic was a flagship and so was the Mary Rose). GNOME needs more polish than that to be on par with KDE 4.5, IMO. Feature for feature, there is no comparison.