Hi,
I read a lot of problems regarding Mavericks and P8/P9 and today I gave them a try today. I did a full backup and I upgraded my iMac to Mavericks. Was fine. My Win7 on P8 was still running as fine. Then I upgrade to P9, being keen on the fullscreen features which was also fine without any glitches. Everything works so far, also Win7/P9 fullscreen on one or all monitors (I have two external monitors).
Coherence is working, too. Machine is running for about 6 hours now. Hope this is continuing...
regards