I have had the pleasure of using an APT96600 controller in conjunction with a QS 14kW / 34kW hub-mounted Motor on a converted Aprilia rs125 2-stroke motorcycle. It is a very powerful and completely silent and reliable controller - even doing a good job of powering a motor much larger than it's rated capacity. I am so impressed with this controller that I have ordered the more powerful AE961000 (1000A) controller from QS Motors.