I have the ST 500 step thru.  i have put 2100 miles on the bike, no imajor ssues.
Bike has all the features, throttle,  internal rear gears, ( no derailer )  lights, fender, bike rack,  lcd display speedometer, odometer, battery level, etc..
Bike has penty of power.
I like the front wheel motor because any bike shop can repair except for the electrical parts.