I have the M5A99FX it's currently being RMAed for the 2nd time in 1 month.It's fast as heck but the build quality is very poor.1st time the board would not power up.Sent it in and got it back and it worked very well for 1 1/2 weeks until the southbridge chip overheated and burnt out.Sent it in again and I'm now waiting for the replacement board which should be here Wednesday.
I was going to get the Sabertooth board but the M5A99FX was on sale for $139.95 But after reading the reviews and such I'm glad I didn't.There were about 50 of them on Ebay that are burnt up but those were all Rev.1.01 boards so they may have fixed the problem with the VR modules.
Crosshair board is a very good board with Top notch build quality and components.
M5A99FX
DDR3 2133(O.C.)/1866/1600/1333/1066
Realtek ALC892 Audio
Realtek 8111F Lan
4 (x16, x16, x4, x4) Pcie slots
Sabertooth
DDR3 1866/1600/1333/1066
Realtek ALC892 Audio
Realtek 8111F Lan
3 (dual x16 or x16, x8, x8) True Dual x16 pcie
Crosshair
DDR3 2400(O.C.)/2133(O.C.)/2000(O.C.)/1800(O.C.)/1600/1333/1066
Supreme FX III Audio
Intel®, 1 x Gigabit LAN
3 x PCIe 2.0 x16 (dual x16 or x16/x8/x8) 1 x PCIe 2.0 x16 (x4 mode) 2 x PCIe 2.0 x1
3 Way SLI/CrossFireX
I would get the Crosshair Just because I HATE Realtek Audio and Lan.And if you ever want to pop a cheap DX11 Nvidia card in with an ATI card you can do it.This enables Nvidia accelerated PhysX.This typically results in a smoother gaming experience and additional visual effects.