I've seen one of the Elite's with the 23 cu ft refrigerator, and it does appear to require a modification of the "standard" cabinetry to fit it in. That model that I saw was also equipped with an inverter.
If you want to see pictures of that Elite with the residential, there are some photos here:
http://s1190.photobucket.com/albums/...SB3/?start=all
As for us, 18 cu ft is just right to go into an existing refrigerator cavity and is about 5 cu ft more than what the Dometic was. Since we don't normally keep a lot of food in ours, 18 cu ft is plenty big.
Terry