I noticed no one mentioned the ride, I find that 38-40' MH's have a longer wheelbase which often gives a better ride than a shorter WB MH. Drive over a concrete Interstate with the freeze strips, section strips and you will often find a better ride with the longer wheelbase. I also believe the CCC is greater on the longer MH's. My MH is listed as 38' model but measures 38'11". Have never found a CG I did not fit in and many that I could fit a 45' Tag model.
Buy the one that you like the floor plan and features you like the best. Often some buy a shorter model and later end up buying a bigger one.