For me, almost everything is working just fine on my Z68x/2500K system with an Nvidia 670. The only problem is it seems my geekbench scores are lower and I'm not sure if it's because of power management or because of my 2500k not being fully overclocked while booted in Mavericks. Usually with my overclock I get about 12,500 in Geekbench but I'm only getting 9000.
I'll try NullCPUPM later and see if that makes any differences.
Using exact same Clover boot as my ML drive (just choosing to boot from Mavericks instead at the OS selection screen).