I never had any handling issues with my MH when not towing, or when towing a Mazda CX 5 on a tow dolly. Maybe I would of had problems towing the Mazda in strong winds? I did use the tow dolly for almost 6,000 miles, but don't recall any wind related issues. I started towing an F 150 4 wheels down and would occasionally get a tail wagging the dog feeling. That little annoyance turned into a white knuckle driving experience while driving in some strongish winds, while driving across Texas last Nov. I ended up unhooking the truck and my wife drove it the rest of that day. You could still feel the wind while driving the MH without the toad, but it wasn't that big a deal.
When I got home I had a shop install a Super Steer rear trac bar. I "read on the internet" that it would cure the problem. Unfortunately in my case I don't think it made any difference at all. I've been on two trips with winds in the low teens and it feels exactly the same as it did before adding the trac bar. Perhaps in stronger winds it might cut down on the white knuckle experience, but I just don't think it will. :(