Hey Jeff,
I am an Ultimate Trailer authorized dealer and have owned and used one for three years and have 99% loved it. It's super quick and easy to load by yourself it's much lighter and easier to pull than a conventional enclosed trailer and its pretty much theft proof.
When I travel and stop overnight or store it outside my shop, I activate the air bags and set it on the ground so it can't be towed away. I also use a tongue lock but it's not really needed because without a key to power the control panel, the air bag compressor can't be powered up to raise it to towing height nor can the top be raised to access what's inside. If you are interested in one call or PM me and I will get you a member discount on one.
The main downside to owning one is everywhere I go I am constantly asked "How do you get inside your camper?" Everyone seems to think it's a teardrop camper but they are stumped because they can't find the door..lol! When I hit the button and the top raises up and the rear drops to the ground, jaws drop.