I cannot justify over $100 for a servo but Like everything, Good, fast, cheap. choose 2!
I have always tried to stick to the same brand servo as radio i am using thinking the compatibility of them will be better. Kinda like LRP motors and speedies. The X12 does not play nice with some speedies. . I use a sdx801 and m11x which is a great combo. I am not sure if it's the radio that helps make this combo so good but I'm very happy with it. FWIW This is the servo Marc R used to win the last 2 touring car worlds! And with a lot of the top euro drivers using Sanwa they gotta have something going for them!