I agree with Brandon as well, I run JR 8917 hv's - 8717hv's, with that being said I run the small white round servo wheels, when I crash these turn out to be the weak link thus saving the servos from internal gear failures, (HOWEVER) I will say the "Pots" on the inside my suffer and even accelerated failure if it is a Nitro due to vibrations. I have had this happen a few times with JR servos and fortunately was able to figure that out unfortunately after it caused yet another crash when i use to fly Avant's. The servo once a load was put on it and in flight, I noticed the swash jumping. What was happening was the servo was seeking center due to the Pot beginning to fail. I guess what I'm trying to say is just be very aware of this issue because it is possible!!!
Also I will go on record to say Tim Jones is running Pro tek 250t and literally you can grab the head and try to twist it while powered and YOU WILL NOT get them to budge or even start to Buzz. Damnedest thing I have ever seen. These servos are Solid as a Rock!! Worth looking into, $129.00 each. These little Jewels will take the abuse of hard flight and a crash..
Kevin