For me personally, I would surely use a tow dolly for one-time use, to get from point A to B, like moving across the country. Also as a snow bird moving south for the winter and north for the summer. In both scenarios, I would rent the thing. But dealing with a tow dolly during the types of trips we take and places traveled such as national parks, monuments, etc. I think it would be too much to manage.
Towing 4-wheels-down without a tow dolly, when in a rush, we can unhook and drive away in the tow vehicle in 45 seconds and re-hook in 3.5 minutes. And there is no third wheeled thing to deal with.
Dynadave brought up a good point about the width of a tow dolly. It just might be wider than a PC.
If you are seriously considering buying a tow dolly, rent one for your first trip and see how it works for you. Maybe our comments are unfounded for your types of trips. Cost to rent is cheap, and cheaper yet if you return it to the place you are renting it from.