I avoid the NuVinci bikes at all cost. I did ride one today(1st time in months) and I thought it had the proper gearing, but it was hard to tell because the wind was so strong, and the weather still being so cold, so the legs and lungs don't instinctively go full throttle.
These Cit-E-bikes aren't really pedal assist bikes, but e-bikes with a cadence based throttle. You can pedal faster to go faster, but you are not working one bit harder.
I did try the scooters in Austin, plenty fun, but I can see how they can be dangerous. The rake on the front wheel is basically non-existent. Tried to take a selfie and pix of the speedo while going at max speed (18mph).. basically it was impossible because it won't go on a straight line without both hands on the handlebar. And you better be focused on steering with both hands all the time because any road irregularities will throw the steering off. It was still plenty fun though, pretty much can go full throttle the whole time in the streets, except going around turns, you can't bank into it, so my turns frequently goes into opposing traffic lanes.