I have a os70-fsII on my 4*60 kit but haven't had good enough weather and time to test fly it yet.
Did some research and found that most people prefer a .91-fs, but that the .70-fs will do for normal sport flying.

I'm convinced the .70 will be perfect for me. I'm not into aerobatics and just enjoy zipping around.
I figure I'd go 1/2 throttle with the .91, so why not use the .70 and go 2/3 throttle? ... Well, time will tell, but theoretically I like this combination