Yes, we have them. We used them quite a bit when we bought them five years ago, but only on designated cycle routes as we found to our surprise that cycling along the roads was actually very unnerving, as we live on the outskirts of a city and the traffic is horrendous. It didn't help that the one I bought was slightly too big for me - I stupidly ordered it online instead of trying one out first.
So our bikes have been languishing, unloved, in our garage for over 3 years, and now the batteries need replacing (these are so expensive that it really isn't worth trying to revive our interest in the bikes!).
If we lived in a quieter area, I am quite sure we would have used them far more - our rides along cycle routes were really enjoyable, I absolutely loved the freedom of being on a bike and being able to stop whenever I wanted to without having to look for somewhere to park! We found we didn't need to have the motor running all the time - on level ground or downhill, we turned it off, only using it if we needed a boost going uphill, so this helps to extend the battery life between charges.