My wife and I bike huge hills with the hilltopper system. We love it...
Just yesterday I topped one of the worst hills in the area beside a road biker (buff and standing on the pedals!) and he was amazed that this old guy was keeping up with him!
I have two kits and they have worked great. I have had good service from them as well.
Maybe I got lucky with the product and the guy I spoke with on the phone...