The only problem is my big butt. The Aqua Magic V came with the RV, an I recently saw an article on this new Residence model which is a little higher and has a more elongated bowl. I am one measurement away from ordering up a Residence model to give it a try. I am almost certain it will fit in my 31FS without a problem.
This was a pretty easy swap. But, I did have all the necessary PEX tools for changing the 1/2" pipe. It required a 90 degree fitting I picked up at Lowes for $3, since the new toilet water connection was not pointed down, but rather parallel to the floor.