My upcoming upgrades are XO brakes, Bontrager RXL 680mm 15rise bar or the Spesh comprable one, S-Works Ground Control tire, or Fast Traks all around...lighter SRAM cassette, and drill my guide even more.
I've ridden Fast Traks around here before and it's ok. 2.2's so it's a deeper tread and wider. It's mostly a hardpack with some sandpits and mostly rocky and rooty terrain. Lots of limestone and slickrock on some trails, and hardpack sand.