From the FAQ What if I buy a mattress made of lower quality materials? Or, in other words, what if I buy an "S-brand" mattress? This is a riskier proposition, but one that I totally understand. I've lived in places where my only options were buying sight unseen from the internet or buying an "S -brand" bed of potentially unknown materials.* While S-brand's spring systems are generally solid, most of their comfort materials are on the lower range (1.0-1.5lb/pcf polyfoams; or < 4.0lb/pcf memory foams) and will quickly develop a "thinner and flatter" feel within a few months. If the mattress you're buying is a pillowtop, then this breaking in process can feel like a rapid loss of support and lead to an uncomfortable "sink" in the middle of the bed. Conversely, rapid softening of the comfort materials can also allow you to engage with the support system more easily and thus increase the support of the mattress. So it's complicated. I would generally avoid S-brands if you can. Answer from mattress411 on reddit.com