The Americans are really nice.They seemed the most solidly built of all the "non-custom" coaches we looked at when we were shopping. A good one of those will serve you well, I think.
"Greatly" limit your options? Hmmm. Every 5' increment from 20' up limits to a certain extent. I guess the three biggest questions are: mostly East (favors shorter) or West? Mostly commercial campgrounds or national/state/local parks (favors shorter)? Full-timing (favors longer) or vacation?
It's for sure there are people out there in every size, shape and color of RV doing all of the above. All RVs are a big bucket of compromises. Focus in on what's most important to you and let the rest fall where they may.
1994 Blue Bird Wanderlodge WB40