From someone that bought a lot of them and went mid practice to switch out a plane full of servos, there is something weird with atleast the ones I had. When I switched to the current 8911 servos it made a noticable difference. Especially not needing to trim almost every flight a click or two. I am keeping what I have on some of my planes but for IMAC my experience is a different servo works better for me. For a servo that cost $100 ea, i still think they are great. But, when you send more, there is a cost benefit.

I don't use power expanders or anything like that. Just multiple inputs for power in 2 receivers and servos plugged into the receiver's