Can't help you with the swiveling seat, but welcome to Super C stardom! We came from a Class A and simply love the much improved driveability the Seneca has. That alone was enough to convince us to make the switch. You will not be disappointed in your new Seneca (but have reasonable expectations on things that will need to be fixed straight out of the box). CYa down the road.
Rick with Lori, Two Pekes and a Shih Tzu
16 'HJ' Jayco Seneca 37 Topaz
16 'JK' Jeep Wrangler Sahara Unlimited : Falcon All-Terrain tether
08 Fleetwood Bounder 38P (gone but not forgotten)