So I moved to 9,500ft in November of '05. I just got my bike back from the shop a few weeks ago. They tuned the bike, adjusted all the valves, new suspention, new tires, new brakes, new fork seals, new rear sets, and a tune up. I havn't felt that kinda power from the bike since before I moved!
BTW: The new dual compound tires from Michillen (haha) are awesome, I recomend them.