I've had great success with BBS02's, but think hub motors are superior for street travel unless the routes contain extremely steep hills. IMO, rear motors are better unless there is a compelling reason like an IGH, belt drive, cargo bike or whatever to use a front conversion. Perhaps the most important decision is the size of the motor; watts can range from 250 (3.5 pound minis) to multi-thousand (25 pound behemoths).