Jayco construction.
https://www.jayco.com/products/travel-trailers/2017-jay-feather/construction-detail/Along with construction, access to the fridge, bathroom and anything else you'll need to get to with slide in is important for rest stops and loading, unloading at the house. For me, a full 80" bed is important. Stand up room in the tub/shower is a must. For towing stability, I prefer a trailer with axles well aft of center and little opportunity for added weight aft of the axles. Some trailers tow well. Some are on the verge of sway by design to achieve a lighter tongue weight. Fresh water tank should be over or slightly forward of the trailer's axles. Check access of shore power, water and sewer hookups. Some are in very odd locations.