I have a 6exa, I think the best thing is digital trims because after you turn the power off you don't have to worry about bumping the trims accidently. I wouldn't worry about how many models it holds. If you are good enough to own 10 planes, I think you would be proficient enough to retrim a plane if you have to in about 2 minutes.

The only thing I don't like about the 6exa is that it don't have dual rates or expo's on the rudder. I don't know if the other models do or not, but that would be really nice, specially for taking off.