All very good points but no one seems to have mentioned the weight as it affects the motorhome. It would need to be a substantial vehicle to have the available payload to carry both the carrier and the bike AND since all of this weight is behind the back axle you are in danger of overloading the back axle and doing a wheelie in the camper.
We have an RV but could not carry that many KGs plus the easylifter without problems. That why we www.unibrake.co.uk a Smart ForFour or tow our 'bike in a box'
There is less rear end load with a Hydratrail due to the bike/scooter sitting virtually over the trailer wheels. Certainly less than I currently have with my Excalibur trailer.