I've been using a Demco KarKaddy dolly for over 8 years & 47,000 miles. If done properly one person can load, tie down the toad in less than 10 minutes and never have a problem with loose straps. Unloading can be done in half that time. Campground storage has never been a problem either.
The only drawbacks with a dolly are if you have problems getting down on your knees to strap up and if your getting too old moving the dolly around for storage.
Anyone interested in the proper procedure send ma a “private message” and I’ll responded.
Dave