On desktop I'm using F10 for cca one month and it's really stable for me. F10 seems to be much more better release than F9 ;-)
On notebook I'm afraid of 2.6.27.x kernel, because with 2.6.26.x I had problems with WPA on Intel 4965, so I'm still using 2.6.25.14 kernel and F9 there. I'll try kernel from rawhide and will see after few moments ...
In preupgrade util (on notebook - F9) I have only Rawhide option (no Beta, no Preview)? Why?