Cant beat this for the price!
I like this more than I thought I would. You need to know your wiring because you will probably be using this on a random motor, but all the wires are there and it works very well. 40 amps provides plenty of grunt to get around. I have mine powering a Bafang 750 watt rear geared hub motor. I had to go through several combos of the hall and phase wiring, but it worked out well. I think its a square wave controller. Not very noisey at all. I love the cruise control on my long rides, it works out great.
I had no problem with this controller, if you know what the wires are for and how to connect the phase and hall wires properly, they dont always go according to color code, there are 33 possible different combinations you must try. Just because you swap blue and yellow phase wires, does not mean you have to do the same for the hall sensor wires. It has been my experience that sometimes you have to do the phase and hall wires separately. But it takes time and a bit of experience to do, just because you a degree does not mean you have experience. I only have a Grade 7 edumacation :)
You MUST make sure you throttle is wired correctly and you do NOT have the brake cut out plugged in while doing Phase and Hall wire's.
The only reason this product got a 3 is because of the rather skimpy traces on the board itself, I beefed them up with nickel strips for battery packs, much easier to solder on than a solid round 12g wire.