The side couch/pull-out on the 19 has a bit of a different configuration than the 17' because the rear closet runs full width IIRC. So it uses only 2 cushions instead of the jigsaw puzzle of 5 cushions that the 17' does. The bed is the same size I believe. The front dinette is the same size between the two as well I think.
At any rate, the cushions they had from their 17' didn't all fit in their 19', so they kept them and when they
sold their 19' they still had them in the attic.