How much does the length of a TT affect driving?

Weight is your first consideration. Wheel base on your truck is another. The shorter the wheel base, the more sway. One of the biggest differences I noticed was when I went for 26ft to 32 ft was tracking. My 26 followed me where ever I went. With the 32, I had to swing wider. This was more obvious on narrow mtn roads. I found myself staying on highways more and hesitant to go to the campgrounds we loved up in NC. I downsized back for a more comfortable driving experience.