I started running Savox servos last summer, pretty much be cause I was getting a super deal on them locally, so I decided to try them. Honestly, I haven't had a single issue with them yet. I also run Hitec and Futaba servos (I have a lot of different RC's).
Spektrum is the only brand I do not use any longer. We had a couple issues with Spektrum gear with my wife's RC's. The first one being DX3C steering spring breaking on the second trip to the track, then a compatibility issue with a AE ESC which kept causing transmitter and receiver to loose their bind, then we had another compatibility issue in a crawler with a winch controller.