Hi Stephens,
The first thing I would suggest is to read this post and the links it includes which is a step by step guideline that can greatly increase the odds of finding the best possible quality and value mattress that best matches your needs and preferences.
As you can see from the links … the quality of a mattress is only as good as its construction and the materials that are in it and the quality of a mattress can only be determined by knowing the materials that are in the mattress. Its “value” can only be known by making apples to apples comparisons to other similar mattresses.
The memory foam in the Comfort revolution is 5 lb which is good quality but I would want to make sure that it was either American made or was CertiPur certified (and had no fillers). I would also want to know the density/quality of the HD base foam (although it’s probably in the 1.8 - 2.0 lb range which would be suitable for a base layer).
Finally with a quilting layer that includes 2 inches of soft quilting foam, I would want to know the density of this as well because this could be the “weak link” of the mattress (the softening of the foams in the upper layers or quilting of a mattress can lead to the loss of comfort or support over time which isn’t covered by warranty). The quilting foam would modify the feel of the memory foam below it and increase the resilience and breathability of the upper layers (not quite as much motion restriction as memory foam) and reduce the temperature response of the memory foam below it which may be a preference for some but not others (who may want a more traditional memory foam feel).
In addition to this … the most important part of a mattress purchase is that it is suitable for your individual needs and preferences and if you don’t have the chance to test it in person then there is no way for you to know how well it may work for you unless you are dealing with someone who is very knowledgeable and experienced at “fitting” the mattresses they sell to different body types and sleeping positions and this expertise doesn’t really exist at Costco. In other words … you are rolling the dice in terms of its suitability for you which means that regardless of the “value” of the mattress the good return policy of Costco may be the most important feature of a mattress purchase there. 4" of memory foam with another 2" of soft polyfoam over it is a fairly thick comfort layer and may carry some risk of alignment issues for back sleeping especially (depending also on your body types).
If your new baby will be sleeping in the mattress I would avoid memory foam completely because I believe that memory foam is not a good choice for babies, infants, or young children. There is more about this in post #2 here and post #21 here (and many other posts but these will give you the gist of why).
I would also take online reviews with a big grain of salt because while they may have some limited value (particularly about the retailer) … they will tell you very little about the quality or value of a mattress or how suitable the mattress may be for you. There is more about this in post #4 here.
A mattress is always a combination of softer upper layers for pressure relief and firmer lower layers for support and the balance between them along with the “feel” and other properties of the materials in the mattress are part of the “art and science” of matching mattresses to people which is just as important if not more so than the quality and value of the mattress itself. While based on materials alone this mattress seems to be “in the range” for side sleeping … it may have top layers that are too thick/soft for some for back sleepers and may present a risk for good alignment. They certainly appear to be thicker than your current mattress.
Overall I think that in spite of the potential “weak link” of the mattress that it has likely has reasonable to good “value” (depending of course on the answers you get and on how the “gaps” of the missing information are filled in) but this says nothing about how well it may match your needs and preferences in terms of PPP (Pressure relief, Posture and alignment, and Personal preferences). While I understand the desire for good value … the suitability of a mattress and the ability to either test it in person or work with a knowledgeable and experienced manufacturer or retailer that can “match” you to a mattress is at least as important a part of the “value” of a mattress purchase.
Overall … regardless of where you end up making a purchase … I would do some local testing first to get a clear picture of what may work best for you.
Phoenix