I've had a little too much problems with Kubuntu on my laptop, plus I felt that the Kubuntu desktop experience has some strange bugs. After seeng what people recommend as a KDE based distro, I decided to try out Fedora 19 KDE spin.
Like KDE, I had also tried Fedora a long time ago. I also used RedHat (the original desktop RedHat, not Enterprise) a long time ago. At some point I started using Debian, and then Ubuntu. I have dabbled in other distros, but at the time apt-get was so much better than anything else that it was almost ridiculous. For some reason I just got stuck there.
This was not however the purpose of this post, I was going to compare the experiences between the two. This can not really be an Ubuntu vs. Fedora comparison, since I haven't really tried the "stock" Fedora. So far I must say that Fedora comes out ahead, there is not strange bugs right from the start. I did have the same difficulties installing Fedora on my UEFI / GPT laptop as I did with Kubuntu, I did eventually manage to do it. I did not on Kubuntu, had to install the Ubuntu minimal image and then add kubuntu-desktop. I basically had to nuke the whole partition table to pull of the Fedora install, but I managed none the less.
Fedora KDE is definately not bug free, but it seems a lot more polished than Kubuntu. The clock/timezone work from the start, and I haven't really run into any other strange bugs. The Mobile Broadband worked from the get go. The only really strange thing I have noticed is that Apper doesn't show any kind of progress while downloading. This can be a bit strange in big updates or installs over mobile. I found a bug report about this, but it seems to be intentionally turned off because of some bugs in yum.
I will run Kubuntu on my desktop, atleast for the time being. But I will try to test Fedora on my laptop in the meanwhile. And I'll get back to the whole experiment once I have tried Fedora KDE spin a bit more. Now I have spent the most of my two days using it trying to get the install right.