Yeti is an excellent bike to race with. I know that disc brakes are 'heavier' but braking is everything, especially in the corners. Racing on a hardtail versus full suspension will have its advantages and disadvantages, mainly weight and climbing for the hardtail, but you will descend quicker on the Yeti and brake easier, especially in wet or muddy conditions. Fine-tuning the rear on the Yeti for minimum bob will also pay off.

Frames made in Colorado: 303 DH, AS-Rsl, 4X, Special Projects, and all race bikes and prototypes.
Frames made in Taiwan: AS-X, DJ, 575, ARC