I've got a Bafang BBS02, it has done it's job quite well. Only real complaints are the very small amount of threads that are left for the lockring to grab if you install it in a 73mm bottom bracket shell, and that it only has a cadence sensor instead of a torque sensor. Feels like you are spinning your feet to activate the motor, rather feeling like the motor is adding power to your pedal stroke like on a bike with a torque sensor. The kit can put out more power than I feel safe using on the bike it is installed on, but you can just use it at lower power levels.

Another option would be to get yourself a bike that is more upright, makes it much easier to go at a pace that is slow enough for someone else to keep up.