Just got to it last night. No obvious issues so far. but i have been running on yosemite for awhile despite a few bugs in finder and mail.
10.9.5 added to bundle at Clover UEFI on T420 Guide
20-September-2014 - 10.9.5 and 10.10 DP8/Beta Update
- Clover updated to v2912 (2890 is latest posted)
- FakeSMC updated to 6.11.1328
- Added drop table MCFG for Nvidia/Optimus (mixed gfx)
- Added drop table DMAR so VT-d does not have to be disabled
- ACPIBacklight.kext - v2.0.3 - with modified code to fix/workaround for LCD brightness in Yosemite.
- Updated 10.10 kexts folder (10.10.DP8 AppleHDA and BroadcomBluetooth kexts + Hackintosh Kexts)
- Updated 10.9 kexts folder (10.9.5 AppleHDA and BroadcomBluetooth kexts + Hackintosh Kexts)