When I was working I hit almost 40 states over the years. Sometimes for a few weeks, other times for a few hours. I think an important factor not mentioned so far is how long will you be in one place.
A 25 footer will be much easier to haul from town to town every few days than would a 35 footer. But for a month, you'll appreciate the extra space. My experience is even our 36 footer starts to shrink after a month.
But those posts on weights are very important if you're looking for the larger units.
Since you're new to RVing, I'd suggest buying something a year or two old from someone who really is motivated to sell it. There's a good chance whatever you pick, you'll soon learn what it is you want out of the trailer. With luck and having gotten a really good deal, you can get most of your money out of it when you're ready to get the one you really want.
