Aside from the adjustable foundation question, this post is one to read. Now, I personally feel that coil spring mattresses tend to sag too soon for my liking whereas latex should be be more resilient longer. At least that has been my experience with coils and thus my recent foray into all latex. And, perhaps most importantly for me, the configurability of a latex mattress with zippered cover opens a lot of possibilities in terms of rearranging layers, swapping layers, and even periodically flipping layers (certainly Talalay can be flipped). So even if 2-3 years from now I feel a bit of a sag, I could for example, just replace one layer and get back to a firmer feel.