Could be the dual-pane windows, tank heaters, back up alarm "Lady", Banks stuff, warmed bidet, and Onan Gennie?
I don't know for sure, but I think the XL designation is a moving target.
I just realized that my 2005 won't be allowed into some parks next year, although it looks and operates like new!
2005 Georgetown 342DS XL, Full Banks Package
2005 Liberty Renegade 4X Toad
1989 Wrangler Sahara Toad
1984 19.5' Beachcraft i/o 5.o liter, 4-bbl (and you thought your Moho sucked gas!)
D/W Carole and Maggie the Teacup Lab (Black Chihuahua)