Same here. At 6.0v my M17 has more servo speed than I can handle. Does not matter what brand ESC or servo. Part of me is reluctant to "have" to go to 7.4v to get my speed back. Maybe I'm imagining things, but with the NB4+ throttle response feels a bit softer and delayed. But that could be due to the difference in the default throttle/brake ratio compared to my M17.
Thanks!
What I meant to say is i run an nb4 plus also and I’ve never had any issues with speed