Recently I procured a Revel Propulsion mid-drive. The kit, designed and assembled in OR, was executed well and weighed less than eight pounds for the motor/controller, display and mounting hardware. This replaced my BB and crankset which weigh slightly more than two pounds, so less than six pounds net addition. The battery and cradle, which mount using the water bottle bolts, weigh slightly more than four pounds. The system is rated at 450w, 60 nm torque so slightly less than most OEM's, but was developed for individuals who like to pedal. I'll post a report about the performance when I've evaluated it thoroughly.