BRAKE CONTROLLER
I have not heard of a 'manual' brake controller any time recently. It sounds like it either has to be activated manually (press a switch every time you want to stop), or is 'binary' (brakes either full on or full off. In either case, I would avoid it like the plague...
You want a controller which is easy to install and set up, requires little or no maintenance, and provides the appropriate amount of braking in all conditions.
There are actually 'levels' of automatic brake controllers. Most will work ok, but some need to be 'set up' more than others. I like the Prodigy, which uses some kind of motion sensing or inertia sensing to determine how much braking to do. There is another one, I forget the name, which has a sensor on the brake pedal for how much it is pressed. That might be a bit more accurate, but a bit harder to install than the Prodigy.