How does the edge support hold up for couples?

Exceptionally well, this mattress's standout at a 9.8 edge score. Edge sinkage lands near the firm end of the 2.50 to 4.58 inch range, with a foam-encased coil border keeping the side rigid, roughly three times the support of a plain foam edge. You can sit on the rim to dress or sleep flush against it without rolling off. For two people, the full surface edge to edge stays firm and usable.