It seems from the reviews that this product is hit and miss with respect to motors suddenly freezing, in fact, it happened with one of the 2 I ordered.
But, get your hands on a working model and: OH BOY is this thing fun. I'm 6'3, 240lbs and it pulls me like I was shot out of a cannon. In fact, it pulls me and my 2 boys holding on to my legs. It is so much fun and exhilarating. I highly recommend it