RE: What do extreme speed guys use for servos?
I have used Hitec servos with some success. I like their smaller servos more than the big ones, but I've never had an in flight failure. I use 645MGs in my big Westerner, and have used 635s without troubles. 69oz torque on 4.8V and 89oz on 6.0V. They are very strong and are standard servo sized.