We installed a foam mattress and, ultimately, killed the control board on our bed lift-the foam mattress was a bit too stiff. It may have been coincidental, but I had to take the bed mechanism apart so that I could get the slides in on our Ellipse. Just like a boat-Bust Out Another Thousand....
Chuck and Jo Ann Culpepper
(Plus Max, Minnie, and Midget)
2016 Ellipse 42QD/2015 F-150 Eco Boost 4X2 Dinghy
We replaced the dual air mattress in Oct 2018 with:
Denver Mattress® 326389 - Supreme Euro Top Narrow
King Mattress with Radius Corners
Supreme Euro Top Narrow King Mattress with Radius Corners
(326389) by Denver Mattress®. 1 Piece. 72" x 80" x 11". Wake up
relaxed and rejuvenated with the RV Supreme Euro Top all-foam
It has the radiused bottom corners which match the foundation plywood.
Holding up very well. We're both quite happy with it, but we really disliked the factory installed unit, a real POS/PIA.
Saved the top piece (head-end) of black wrapped foam from the original air frame siding. Used it to sort-of fill in the top gap after swap-out.
Many foam mattresses are shipped coiled up and bound, you move into place and cut the bands and let it relax back to full size for some hours, if buying from store they do it for you or if dropped shipped it is NOT flat but ROUND !!