Last month I changed my 9C front hub into a rear hub, process posted here:
and resulting in finally having front disc brakes plus rear regen brakes, with 26" rear and 24" front.
One primary reason for the changeover was to get those disc brakes, and another was to be able to use a better suspension fork, without ending up with the death wobble because of the geometry change.
This also let me get much more traction with no wheelspin, and far less tire wear, since there is now enough weight on the motor wheel to keep traction as I startup from a stop, even on poor road surfaces, so far. Sand and gravel can still wheelspin a bit sometimes, but I am rarely on anything but asphalt.
Then I swapped to 26" front so I could *also* have front rim brakes, as even the disc is not sufficient to be able to lockup the wheel by itself. While I don't ever want to lock it up, it's good to ahve that much braking power available, so I can stop in less than a few bike lengths. ;-)
I also modified the seat, after having planned to do so for nearly a couple years. Now it is bent forward at the midpoint in back, which makes it more comfortable and lets me relax in it better while riding.
Overall it is a much better ride than previously.