Assuming that the unit can cool the trailer with 4 ducts, the thing to check would be whether there are cool or hot spots in a given area. So, if possible, check the AC on a good hot day, and while the unit is running, sit or stand in all different areas where people would normally be and see what the comfort level is. Another factor to consider is whether you will be spending a lot of time in very hot locations where the AC could be a problem....and that's hard to do unless it's a hot...as in the 90's with bright sun when you check the AC operation. Otherwise, it's down to seeing if you can get responses from owners that have given their unit a real workout in hot temps.