I love the Sabertooth. Everything about it. It's one of very few P55 boards that give you great spacing for sli/crossfire. It is a little pricey, but you're looking at heavy duty build quality, top shelf cooling, and of course the pci-e layout.
It also offers great spacing for crossfire/sli. Much better nb/sb/mosfet cooling, 16+2 voltage (vs 6+2 of P6T and P6T SE), and an additional ethernet. It runs about 50 dollars more, but at the end of the day the extra chipset cooling alone makes it worthwhile imo.