I used Clover to install Yosemite on my trusty old Dell Inspiron 530 (based on P35 chipset).
Sleeps ok (screen goes off instantly, then 30 seconds later the fans and power shuts off).
Touching the keyboard key wakes the system but the screen is black and Caps Lock light does not turn on/off.
System is frozen and the only way out is to keep the power button pressed.
Maverick sleep/wake works fine on the same system (using Chimera as the boot loader).
May be its a Clover issue ?
I am now trying to re-install using Unibeast but just cannot get the installer to boot. I tried -x npci=0x2000 GraphicsEnabler=Yes, maxmem=4096, etc, etc. I have a Geforce GT240 graphics. -v shows lot of output and even see nvidia driver being loaded. Screen clears and the system is hung.
UPDATE: I eventually managed to install Y10.10 using Unibeast (had to hack Unibeast by adding my DSDT.aml from Mavericks for the installer to boot). Implication = Unibeast does not work on any PC without tweaking. Anyway, installed 10.10 fine, did the post install stuff and seems to work fine. BUT wake from sleep does not work anymore. Sleep still take 30 seconds to sleep (turn off fans, etc) but Wake using power button or keyboard hangs the system.
CONCLUSION: Wake from sleep problem is NOT related to Chimera/Chamelon OR Clover but with Yosemite. Awaiting 10.10.01