I have got my Dell Precision 690 running 10.8.4 almost flawsly minor things like not wanting to sleep or shutdown completly sometimes are the only real issues I am running into right now.
I am using my SAS controller, HW raid will not work with OSX.
Disable LPT SERIAL and FIREWIRE PATA and Floppy CPUID, the rest of the performance settings should be enabled
If firewire is enabled you will not be able to get your ethernet to show as en0 and will not be able to use the appstore and software updates. If you have CPUID will kernel panic
I used myhack to make my OSX86 install media http://myhack.sojugarden.com/guide/ .In the install media since I am using a hd6670 ATI GPU so moved my ati600controller.kext from /s/l/e to /extra. For the SAS Controller use the attached AppleLSIFusionMPT.kext rename it and place it in /s/l/e/. As far as SATA goes i am not sure if this will work on the installer disk but using a -f tends to show all devices I was able to install mine to the SAS and run these commands to get my sata devices working after install.
cd /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS sudo mv IOAHCIBlockStorage IOAHCIBlockStorage.orig sudo cp IOAHCIBlockStorage.orig IOAHCIBlockStorage sudo /usr/bin/perl -pi -e 's|\x8b\x4a\x00\x00\xeb\x03|\x8b\x4a\x00\x00\xe8\x01|g' IOAHCIBlockStorage sudo /usr/bin/perl -pi -e 's|\x74\x0e\x48\x8d\x3d\x72\x92\x00\x00|\xbf\xc8\x00\x00\x00\x90\x90\x90\x90|g' IOAHCIBlockStorage sudo touch /System/Library/Extensions
For the sound and network to work use the attached files after you install everything. Also attached is a copy of my /Extra folder you may not need all the stuff in it but it should help you get most everything sorted out.
Will update if I can get the rest sorted out