I bought the Giant Lafree E +2 bike with a step through frame. I really like the Yamaha motor and having the motor on the cranks makes for very smooth, non-surge type assist. It has more than enough assist to go up fairly steep hills in 3rd gear and I can easily go 80-100 miles on a single charge. I have been riding it pretty regular, at least when it isn't raining too hard, and the more I ride it the better I like it. I can ride 15 to 20 miles per trip very enjoyably. It really is helping strengthen the muscles in my legs and knees and it definitely reduced the stiffness and pain.
The biggest thing I like about this bike is it is comfortable to ride. Seating is quite upright, the seat is large and soft and the handle bars are in easy reach without being bent over. Not an off road version but fine on paved trails, gravel and grass paths. Would not be great in mud or tough going but that isn't where I ride anyhow.