Dan,
Per your "P.S.", I think you definitely should view a 19, then a 21. Then evaluate whether the interior arrangement (placement of dinette, kitchen stuff, etc.), heights, aisle widths, amount of storage, etc. would meet your needs and wants.
There is something called Two-foot-itus that is mentioned on this Forum. When infected with this condition, Escape owners get an overwhelming desire to own the next larger size Escape, once they see one at a rally or campground. My wife and I are strong: we bought an Escape 17 five years ago, and are still happy with our size choice, but only because we did an evaluation of our use, and decided that it was (and is) perfect for us.
Edit: Something that might help: Here's our evaluation of our choices, and a 1 year later review, that we did way back when. It might stir up some questions or hint at things not thought of yet, so here it is:
https://www.escapeforum.org/forums/f...ater-8933.html
Edit #2: Some of the options and other items in our review are quite different from the current Escape options, ( some things are now even std. features), so a look at the current ETI website is certainly warranted.