RVIA puts them in the "camping trailer" category which also includes pop-ups and tent trailers. I suppose this forum is called "folding trailers" as well, to include more than pop-ups (and I don't know of any manufacturer that sells them by that name).
I looked at a 122S when we still had a dealer in the region carrying Rockwood folders, and was fairly impressed with the build and finish, but concerned about the Cool Cat being under the bed. I was also looking at lightweight pop-ups (dealer was selling off the rental fleet and good prices) so hadn't decided to buy anything (still haven't, three years later, convinced myself I need a second RV for camping at the lake).
I got taken over to look at an A-Liner that someone had just traded on a toy-hauler version of the Rockwood, and was no longer so impressed with the Rockwood. This was a Thursday afternoon. I called back Monday to ask about buying the A-Liner, and it was already gone.
If you have an air-conditioner in one of these, you want the Cool-Cat. It is designed to operate through a wall with just a vent. Lately I've seen manufacturers, to save money, installing low-cost residential window air conditions in a box (rather than having the condenser sticking outside), and these do not work so well, having air flow restrictions and sometimes drainage problems if the RV is not leveled so as to force condensation to run outside. You don't want that.
Jayco/Starcraft is also building these (in a Starcraft plant). I've looked at the Jaycos at the factory showroom in Middlebury a couple of times when passing through, and seen the Starcraft models at RV shows. I've been a bit disappointed about some of the finish details, not up to the quality I've expected to see in Jayco RVs over the past 10 years. I've not seen this quality slippage in any of their motorized RVs, so it may be a plant issue; still, I would expect better attention to be paid to the finish of an example being displayed at the factory showroom.
Tom Test
Itasca Spirit 29B