I have a converted On One 29er with a 750w Tongsheng TSDZ2 motor & throttle and a Haibike with a Bosch CX motor.
The On One is a joy to ride in traffic as it’ll assist you up to around 28-30mph. That’s the kind of speed you need to hold in 30mph limits.
It’s also nice to descend on swoopy trails where it doesn’t constantly cut out at 15mph like the Haibike does.
The Bosch feels slightly more powerful on climbs than the TSDZ2. It clearly peaks at similar wattage to the bolt-on motor. Whatever the figures say.