I would be very interested in the answer to the second question the OP asked:
2) Does it work well with a generator (I use a Champion 3000/4000W generator). It is not an inverter model but does seem to put out stable power. Has run our A/C, fridge etc for 2 years now.
All answers so far seem to skip over that and I hope it is not forgotten. My expectation is that it would probably trip if installed between a generator and the RV but I have no experience on this since I don't have a generator (yet).
On the other questions - my experience is similar to others' in that it makes no appreciable noise and portability is great for some but if one will be keeping the RV for a long time the hardwired options offers more security. All a question of convenience.