We have the 21 FBRS, too. We had only two items on our punchlist after our first trip, which the dealer is fixing under warranty. One was the TV antenna not rotating, which was caused by over-enthusiastic factory application of roof sealant around the antenna base, basically sealing it all together up there. That's fixed.
The other is a switch in the water heater compartment which basically left the water heater ON in electric mode whenever it was plugged in to shorepower, regardless of whether it was switched on or not at the panel. They have ordered the part from Suburban and it's due in shortly.
We are looking forward to many happy days of camping in our 21 FBRS.