As far as the ones you posted, I am no fan of hub drives as they do not allow you to use the power of the motor through the gears.
I am planning on putting a motor kit on a cargo bike. My problem with add on mid drives is they have a very cheap low magnet cadence pedal assist system. I read on endless sphere that you can use the grin phase runner motor controller and hook up a different cadence sensor. If you hook up the new cadence sensor to the cycle annalist you can make it use the new cadence sensor. Grinn has a small 24 pole that might work and even the 12 pole sensors would be an improvement over what I heard is a 6 pole in the bafang bb motor kits. I want at least basic pedal assist and from what you and some others have implied is starting from a stop on these bafang mid drives is not responsive ennough.