Rodrigo makes an excellent point. I've done slapt-get --upgrade religiously going back to VL 5.8. It has never caused breakage for me other than one package (wifi-radar on VL 5.
, and that was when glibc wsa upgraded during a release cycle, something the developers have decided was a mistake. --upgrade should pull in the KDE packages.
eMachines EL-1300G desktop, 1.6GHz AMD Athlon 2650e CPU, 4GB RAM, nVidia GeForce 6150 SE video
CentOS 6.5 (will try VL64-7.1 soon)
Toshiba Satellite A135-S4727, Intel Pentium T2080 / 1.73 GHz, 2GB RAM, Intel GMA 950
HP Mini 110 netbook, 1.6GHz Intel Atom CPU, 2GB RAM, Intel 950 video, VL 7.1