Depends what your truck needs. At 55A and 37V, that's 2000 Watts continuous, which is a helluva lot. That controller has been seen to achieve split second bursts of over 3000 Watts in large heli setups...

Proportional braking is working great for me. If anything it's too strong for my car! Reverse... I would not program that in. The Jazz makes no attempt to brake the motor before putting it into reverse. :)

Just noticed you had the 16016 MGM, so I guess your truck components are already all setup for 5S? The Jazz 55-10-32 will definately be too small on 5S. Maybe an 80-6-18? Or a Quark?