BillMF1,I can totally relate to your wife not wanting to drive the big class A. I, too, was intimidated, and that is one of the main reasons we downsized from a 37' A to our Axis. Loving it!
D.E. Bishop, I would definitely say you are not going to get 13 mpg with the 350 chassis. Would think the Ace with the 450 chassis would get even slightly less mpg! Bringing our new Axis home, we averaged about 10 mpg over 500 miles. When we went to the Tampa show we had not been expecting to find an Axis on the way home, so we had not significantly pared down the contents of our A. We had way too much stuff to bring home! Next trip out we will be considerably lighter, so we are hoping to be in the 10-12 mpg range.. Hope you find exactly what you and the wife want!