My wife and I have a new Gardner latex mattress, medium firmness. They're pretty close-lipped about construction and won't talk ILDs, but they do claim all-Talalay construction - though they spell it Telelay; inside the mattress casing their medium and firm are both 6" of a firmer latex under a 3" comfort layer of less firm latex. (Their plush and ultra plush have a 4" comfort layer and cost a little more.)

I'm a back-and-side sleeper. This mattress was supremely comfortable in the shop on both back and side over about fifteen minutes - no pressure points, cushy support; the firm mattress was a bit unyielding under shoulder and hip and I was a little worried about pressure points. But last night I slept on my back and woke feeling a bit like I was in a hammock. Particularly when I went to roll onto my side and found a bit of pressure against the bottom of my rib cage and the top of my thigh. As if they were on the edges of a hole that my butt had formed during the night. I had to get up an hour early; the mattress was quite warm and shaped for back sleeping, and I couldn't get comfortable in any other position (and felt a little hammocky in that position).

A week or so ago I pulled a muscle in my back at the gym, and now have a little occasional pain in a narrow stripe from the left of my spine out towards the left, and when I was trying to get comfortable on my side I felt pain there. My pelvis was trying to tip up because my legs were out of the hole my hip was in. I've been mostly sleeping on my side - actually on the front part of my side, so my weight isn't so much on my butt as on the fronts of my thighs, and I get better support without the hammocking.

I've read on this site in a few places that latex often sinks in a little bit after a few hours. I'm wondering if anyone can give details, because I only have a week in which to decide what to do. I think my options at this point only really include keeping this mattress and swapping it in for the firmer version - but will that be worse for me? What's behind the hammocking?

Maybe I should just lose weight, but that's not a good short-term solution. My wife loves this mattress.

What should we do?