Fwiw, my Jayco JayFlight weighed nearly spot on to the 5,500 lb "yellow sticker" weight when empty but with a battery and full propane tanks. The dry weight published on Jaycos website is something like 4850 lbs, but don't think it includes any of the standard options or features.
So if you're estimating weight off the yellow sticker on the trailer it should be fairly close, but the website figures probably will be way low.