Hi
I have used a couple of those Power HD's on my Baja, to be honest I wouldn't use them, although the warranties are great, a warranty is no good when the servo locks and ur Baja takes off.
That said any servo regardless of price is going to do the same eventually, as long as you have a fail safe that should be prevented though. On a performance scope you want something that is going to push and pull that throttle arm like theres no tmw, the general opinion at the NYB is Hitec servos or savox, between 30 - 40 quid.
Regular maitainance drying out when damp or wet will obviously maintains performance and life.
regards
Dusty