My next set up may be a mid-drive unit... But, because I actually want to put in most of the pedal effort a rear hub is good enough for me, and so does the wife... She finds it great, good enough to give her that little bit of assistance she may need/want sometimes riding her bike so that it's a fun ride all the time, and not become a struggle/fail on some rides... If I wanted assist that would take me up all the hills around here without me putting in much/any effort I would certainly "need" a mid drive or about a 2,000watt rear hub...