I have an extra disk drive that I plug into my laptop so I can safely fiddle with my operating system settings. Trust me, I've borked my system one too many times to perform open heart surgery on the system I depend on for work. Anyway, I have Mint 14 KDE 64-bit installed as a working OS and another of the same on a spare drive to fiddle with. So......I put the beta PPA's from Kubuntu and Edgers into my software resources. Lo and behold! I now I have:
KDE SC Version 4.9.98
Works pretty good so far. Since my laptop has a derivative of the Nvidia GT7900 chip, I can't use the latest 310.xx drivers.
But the desktop beast has a GT520! I also have a spare drive to play with for that machine too. Linux is so much easier to tweak than (pardon the expression, cough cough) Windows!