Been a while so I thought I'd follow up. Ended up buying the camper, with the first trip last week. About 750 miles round trip. Towing was surprisingly smooth. While I could certainly feel the load there was no sway or bucking at all. I'm convinced that swaying is more a function of unbalanced trailer loading than the size and weight of the load.
Probably a 20mph+ crosswind for about 50 miles and everything tracked very well. Plenty of power to pull, but the roads were midwest-flat. I reserve the right to change my opinion once I hit some mountains!
Commander looks awfully small hooked up. Gas mileage wasn't much worse than I get around town without a trailer. 10.7 MPG one way with a howling tailwind most of the way and 9.7 MPG the other way with calm winds. Not bad for a rolling refrigerator towing a giant 6k lb shoebox @ 65mph.
edit: Had another trip towing through some serious hills near Savanna IL (yes, there are some hills in IL!) Not long grades like mountains, but constantly up and down several hundred feet of steep. Mileage dropped to 8.3. Not good, but still better than most Class A motor homes.