Phoenix, thanks for the links. I guess where I was under the impression a memory foam type (or layered foam construction) mattress was better in terms of durability/longevity is somewhat referenced in one of the links you provided. post #3 says good quality (5lbs or more density) memory foam should last 10-12yrs. Even with the caveat that lesser quality (say medium quality, not top of the industry) 5lb memory foam in the form of a topper from xyz company available through ebay, amazon, etc were to last a portion of that…even cut in half, that suggests it would last 5-6yrs. Understandably, what constitutes ‘useful’ to one may greatly differ from another person’s perspective. Accounting for this huge grain of salt figuring on half the expectancy that’s still a lot longer than what’s available in the upper layers of most innersprings (S brands). I don’t really have the option of an old family run specialty mattress supplier around, so given what I have to work with - the “S brands” from places like us-mattress (chain stores) in the city, or memory foam (compressed and shipped to my door, or diy layers compressed and shipped to my door). This is where I’m confused I guess. So say a good set of innersprings or a good performing poly base, either way it breaks down to what’s in the upper layers taking the direct abuse of the person on top of it, the sharpest compression points etc. Most innersprings (available to me, run of the mill S brands and the like) are using unknown multiple layers of poly and convoluted constructions, resulting in the many voices that say “just bought this mattress, already sagging, already has dips, very unhappy”. Price is in the $400-500 range. Diy or foam mattress in a box type offerings, even if simple construction using 4-5lb memory foams over decent poly are also $400-500. So based on what my options are, in the comparable $400-500 range a memory foam mattress with 5lb foam sounds a heckuva lot more dependable than the innerspring variations. Other options aside from “S brand” are unknowns, like the hybrid visco/innerspring offerings from companies like night therapy or slumber 1, which also come packed in a box - and then aside from questioning the upper foam quality, I’d also be doubting the durability of mystery spring systems used in the base compared to the tried/true innerspring setups used in traditional innerspring brands. Overall, keeping price to price comparison equal, it appears that better quality foams can be had in memory foam options compared to that of competing innersprings and more likely to succeed. Please clarify if I misunderstand the thought behind this…Thanks.