We just picked one up a month ago and love it.
-Check all the cabinet doors and drawers to make sure they open and close properly.
-Check all the edges of the countertop and table (including the outside kitchen). The edge banding seems to be installed very poorly on most of the passports.
-Check the door latch and Door catch on the entry door. They seem to have interference trouble. (If needed have them replace screws on wall side with flat head screws)
-Check all the screws on the lower plastic skirting around the wheels. We had a few missing.
-Check the fasteners on the plastic fridge vent cover on the outside of the unit. We were missing one.
Mods
-Have them install a strut on the queen bed to hold it open or do it yourself.
-Install a lower entry door hook and latch so if you decide you want the door open all the way while camping you can just remove the strut.
-Install a battery shutoff switch.
-BAL extended fit x-chocks for load distributing axle design.
-Power tongue jack (very nice.... my next addition)
-you will need paper towel holder, toilet paper holder, and towel bars. (use fancy command strip hooks for towels in bathroom)
That's about all I can think of for now. Good luck with delivery