My back ain't so hot and I find that cruising with the Wave with the padded backrest is as comfy as can be. My wife couldn't believe it when I told her it was an option. It pops off easily with quick connects if removal is an issue.

Its fine for your wife to suggest the larger vessel since, with a bad back, she won't be called upon to deal with the extra weight of the Getaway, including the increased difficulty in raising the mast!

I love my Wave.