X2 on the Froli. I believe we went with the Star. (1 3/4") The Froli is nice because you can switch out the springs depending on your pressure points.
We stayed with the 2018 factory mattress and then a pillowtop topper. We even keep the sheets, light sleeping bag and comforter on top. (We do have the flatbed model.) I have to give the top a little help pulling it down for latching but it works great.