Chris Cwrote a review of Yeti Cycles SB-66 Race X0/X9 Complete Bike on July 27, 2012
I've been riding it pretty hard these season and haven't had any problems. It climbs pretty well, but that's not its strength - this bike really loves going downhill. Handles great around turns at speed. Handles drops well and the 6" travel makes technical spots almost too easy. The ProPedal and front shock lockout really help with climbing.
Love the SRAM drivetrain, I love being able to shift five gears down with a single button push when I come up on an unexpected hill.
Haven't gotten around to convert to tubeless yet, though I plan to. I may as well, since the tires are very difficult to get off the stock wheels (trust me, you *don't* want to have a flat on the trail with the stock setup.)
This is an ideal bike for Moab and the Wasatch Mountains, where I do most of my riding. It's flexible enough to be a XC rig but it's beefy enough to handle some FR stuff as well. It could probably handle a lot of Vancouver's North Shore trails and Squamish as well. I don't think I'll be taking it to the Whistler Bike Park, though.