Trailer brake controller preferences?



I have read the MB service bulletin on Wolfgang's 4X4 site about how to install one, but I'm wondering if the folks here have any preference between the different types (inertial/proportional/timer), or brands?
I'm thinking we'll probably have around 4500-5000 lbs (not including pax/cabin payload in the ML) under tow.
I realize that some variants require the operator to learn a somewhat new style of braking (other than basic trailer driving principles), and I'm interested in hearing any comments about that. My wife's a fast learner, but I wouldn't want to increase her workload unnecessarily.
Thanks!



