I’ve found it depends on the position mainly. The more you thrust vertically (cowgirl, etc), the less satisfying due to less bounce. On the other hand, foam is better for digging in for horizontal thrusting (doggy, missionary).

This is why about 65% say foam is worse for sex than springs, while ~35% say it’s the same or even better.

That said, I just prefer foam for sleeping. Much more comfortable and I wake up feeling more refreshed with no back pain. We keep a separate guest spring mattress bed for sex (and obviously guests). We bought it a year ago and our sex life has never been better but ymmv!