I've ridden the Stromers and Elby's with lower powered direct drive motors that feel like bikes when I turned the assist power off. Perhaps they keep the coils slightly energized and it would be different if the power were really off.

These kits are mass market in China, and in my opinion, arrive well packaged and are of good quality (aside from wobbly brake levers). Where they miss out is in the quality of the instructions. I've never seen polarities reversed on a battery or the colors on the motor wires be incorrect, as many of the ebike oldtimers who have been involved longer than me with ebikes will warn.