I am not a Desktop Environment  (DE) fanboy, I use Gnome because it's the default DE on Ubuntu. After a while I knew about other major DE : XFCE and KDE. I use XFCE on my older PC.
From what I learned DEs have their own strength and weakness. The best thing about Linux is you don't have to choose, you can have best of both worlds.
Last night I gave KDE a shot on my notebook, an hp 540. I use Ubuntu 9.04. After 188 MB, Kubuntu was installed on my system.
How to install Kubuntu on Ubuntu (for those who want to know):

• run synaptic package manager
• install kubuntu-desktop and all the files automatically included,
• log out, click option and choose KDE, log in again,
  

I was so eager to try it out, here's what I like :

• I love the blue theme and the default layout better than Gnome's
  
• its default setting looks prettier and more functional than Gnome's

But :

• It takes longer time to load,
• It hangs on me on almost every time,
• its network manager doesn't easily let me connect to my Motorola V3xx as a modem, while Gnome's do it easily.

I really want to explore KDE more, but the constant hang blocks me. I'll try harder and learn what's wrong on Ubuntu sites and forums. Until then my conclusion is my notebook hates KDE.

FYI, here's hp 540 specification :

• CPU : Intel Core2duo T5670 1.8 Ghz
• RAM : 2 GB DDR2
• Graphics : Intel 965 (shared 384 MB)

Isn't it powerful enough to run KDE?


Update April 26, 2009:
Well persistence is the key, I keep trying log in to KDE and now it starts and runs just fine. I don't do anything just trying and trying.  So what was causing all that trouble?
In short it looks, feels and works great! The only problem is my network manager doesn't recognize my v3xx as a modem, while it works just fine in Gnome, I have to use wvdial, it works though. But I miss my GUI-ly network manager.

My notebook loves KDE after all :)

keyword : gnome, kde, tryout, hp540