I don't like that the pedal assist is a sensor of some sort on the sprocket - when it starts turning (after x amount of revolutions I presume) the motor engages so there is no way to select the power you want other than through the phone app - not very conducive to adjusting on the fly. How do you slowly pedal up to an intersection for example, without the motor kicking in and trying to propel you to the set 25kmh? Unless you leave your phone unlocked and the screen active, there's a few seconds involved in turning it down.
And no ebrake or emergency cut-off would make me nervous.
Aside from that, how can they possibly make all that in 4kg of weight? Motor, battery, controller, rim, spokes and tyre is included in this weight, someone posted
over on Whirlpool