I tow a 31' fifth-wheel and personally, my preference over a travel trailer.
BUT, consider your legs/knees... going up and down the inside steps to the bathroom and bedroom numerous times a day can get a little much if either of you have leg problems. I don't, but it is still hard at times.
I have toyed with the idea of going to a travel trailer, but would do about a 26'... just my idea of the right length for me.
Using bed of truck is a consideration, a nice cover on it does give some storage room. It is all in what you and your spouse want...
Good Luck and happy trails.