The only issue I've had is not turning ON occasionally, neither pressing the controller or battery power buttons works, both display and battery lights are off. Fix, remove battery from cradle(rear rack) then refit it, works every time, until they day I don't have key on me. Will bring it up with shop as bike is only a few weeks old.
I'll try the high speed pedaling issue Patrick mentioned, suspect it is lack of pedal pressure not activating torque sensor.
In regards to hill climbing, I've not had any issues and my bike is quite high geared, 44t chainring 9spd cluster with 700c wheels. I've had to work hard on a couple of very steep hills but still flew up at 12Km/h compared to 5km/h on my MTB. 95% of hills (sealed roads) are not an issue, NB I'm 75kg and biking fit. The only issue I can see with high gearing is not being able to travel slow enough on hills to accompany riders with normal bikes. For larger unfit riders, a lower geared MTB with higher torque engines would be a better option, especially if is to be used regularly on hilly terrain.
One of my concerns with mid drive system was higher wear and tear on drive train, especially derailleur gears. This may not be issue, as I do a lot less gear changes and use considerably higher gears. I've started using assist levels like an additional 3 gears, anytime I need to get back up to cruise speed after slowing down, counter a bit head wind or short incline, just switch the assist up instead of changing gears. In most of these situations I'm riding without assist or in eco mode.
The lack of gearchange detection has not be issue I thought would as Steps system is so responsive. Backing off on pedal pressure during a changed seems to work fine, you just need to adapt your riding to bike. In saying that, the automatic Di2 system would be wonderful, especially when commuting.
A little trick I read about Walk mode, use it to change gears on derailleur drive train before starting off. If you a strong enough while bike is stationary by lifting back wheel off ground.
