What kind of difference are you referring to? They pull the same down the road, although I suppose there's a bit more drag with the triple axle. I guess you have to watch the longer axles when you turn, but I've not noticed any issues when I went from a double axle to a triple.
I think you're supposed to be more careful making sharp turns, but I need to turn where I need to turn, and if it's a sharp turn, so be it.
If you're looking at a new toyhauler, make sure you get good tires on it when you buy it. Insist on LT tires even if it costs you a few bucks. I guarantee you'll either spend some now, or a lot later. Buying 6 tires at a time adds up. Mine blew after less than 2 years and 8,000 miles. So get good tires when you buy it and save yourself lots of aggravation down the road a bit.