For me the BOB works best, I ride a Catrike Trail. The BOB tracks beautifully behind the trike, I don't even know it's there when riding on the flats or downhill. I try to keep the center of gravity as low as I can. I've had the BOB 2yrs, last year I put an electric hub motor in the 16" wheel with the battery mounted to the trailer deck. Although I've really limited myself on the load configuration, but I'm working with it, the hiil assist is well worth it for me.