I'm kind of with Kevin on this one, however I wouldn't do the Hitec 5645 on primary surfaces. That I would save for coreless, high torque metal geared servos. While I use Hitecs a bit, I still stick a high end Futaba digital on the highly loaded surfaces.

Don't over-install, though - you stick too much servo(s) in and you can over tax your ability to provide power to it/them - not good.

Anything you buy, burn the servo in ahead of time. All the failures I have personally witnessed (for whatever THAT's worth) have either been "infantile" failures (new or within 20-30 minutes of new) or have been seasoned servos, with the gear train failing or the pot got dirty. Each of these failure modes is usually detectable before hand, if you specifically look for them.

Having siad that most of the jet guys use JR, for some reason (hey, wait, I got a ton of them also).