I always throw electronics (name brand too) in something just to make sure they are good. I have a spare 770 that when it came in I used for a track day and put it back in the box as intended to use for a spare.

That being said I had a d772 that was a problem out of the box. I had to send a video to hobbypartz showing it not working right and got an rma quickly. It did cost me return shipping to get a new one but I take that as the risk of using such a cheap servo. Replacement is a year old and still working fine.

If I had multiple problems I would switch brands.

If your going name brand protek servos have been great for me.