The entire point of a high performance seat is to keep one's ass in place instead of sliding around.
I have a natually wide ass, and the Sport SE (manual tranny) seats are decent, but still could be tighter for a performance fit.
So if the driver wants a sofa to sit on, then yeah, do not get the Ricaro seats..
If I had the chance, i will buy a ST Ricaro for my driver's seat on my SE. Fat ass and all.
(I want a bucket my ass fits into like a tight glove.