I'd rather have plywood than press board/particle board.
Somerset, I believe bought the failing Coleman Pop Up line. I'd be cautious on this new owner as all previous owners have folded. I believe due to inherent design flaws in the Coleman line over many many years. I don't know how Somerset has changed the design if it's for the better or worse, but they are unproven, and rare around our parts. I've never seen one or even heard of anyone on the forums even owning one. Somerset is owned by the same company that owns A-liner but if this line is more trouble than it's worth, they could drop it.
I'd probably go with Jayco or StarCraft as they have been proven for years.