The 21SS is one of those trailers that surprises you. It tows like a smaller rig but opens up into a layout that sleeps seven with a full bath. Full Azdel wall construction, a laminated walkable roof, and 6-sided aluminum framing give it a more solid feel than most expandables in the class. Forest River includes 200W of solar with a 1000W inverter and 30-amp charge controller right from the factory, along with 12V thermostat-controlled heated tanks and a radiant foil insulated underbelly, so it's genuinely set up for shoulder-season camping, not just summer weekends. The folding end beds are the one honest trade-off owners mention, so if you camp in comfort-critical company, it's worth a close look at the mattress situation before you commit.
Other expandable trailers floor plans (around 27 ft 2 in, near $46,000), similar in size and price to the Rockwood Roo 21SS.
