If you are interested in non-basement models, also look at older model heavier campers like Fleetwoods and Bigfoots. Other than the height difference, I don't think you are going to get much of a handling advantage with a non-basement model.
The difference is width of floor that is possible and increased side height. Of course, the AC if equipped is higher, but those weigh about 100 lbs. I don't think that difference is significant on a 4000 lb camper. Either way, almost the entire area between wheel wells is holding tanks which will be there no matter if it is a basement model or not. Things like cabinets that weigh a lot are going to be in the same height. The bed and all of that space is essentially the same height as well.