Hi hose406,
The law tags don’t provide any information about the quality or density of the materials or the design of the mattress (layer thickness and order or the layers). It’s like saying there is some fruit in a basket without saying what kind or how much.
Modesto is one of the few places in the country that doesn’t have a local list on the forum so I’ll include one here. I would always call first and talk to them so that you know that they arer willing and able to disclose the quality details of the materials that are in their mattresses.
There are two local factory direct manufacturers close by I know of …
http://www.starmattress.net/ Modesto, CA. Makes latex and memory foam and others and would be well worth a call or visit.
http://info.ikea-usa.com/ See post #3 here for the mattresses I would consider here. I wouldn’t consider their memory foam mattresses though because they use memory foam that is less than 4 lb density so I’m including for reference for others that may be in Modesto.
There are also a few retailers that I would consider and I’ve included the manufacturers they carry that are more transparent and are more likely to provide you with information about what is in their mattresses.
http://www.sleephavenbedding.com/ Modesto, San Mateo, Redwood City, CA. Englander, Organicpedic (a wholesale manufacturer based in Grass Valley, CA. of high quality “organic” latex mattresses that are also more premium priced), and Diamond (a regional manufacturer based in Rancho Dominguez, CA that also makes some higher quality mattresses with “better than average” value).
http://www.woodsfurniture.com/gallery/mattress Modesto, CA. Cannon (wholesale manufacturer based in Fresno)
http://alsfurniture.com/furnishings/mattresses Modesto, CA. Cannon
http://www.mantecabedquarters.com/ Manteca, CA. Cannon, Stress-O-Pedic (regional manufacturer based in Ontario, CA)
http://www.unitedfurniturestockton.com/ Stockton, CA. Stress-O-Pedic
These and your online options would probably be your most likely sources of good quality and value memory foam mattresses.
Serta (or any of the major manufacturers) doesn’t disclose enough information about their mattresses to be able to use them as a guideline based on specs (which is difficult at the best of times anyway because similar quality/density foams can have different properties) and other manufacturers wouldn’t design their mattresses to “match” it so the only way to know whether another mattress approximates it in terms of feel and performance (or is an improvement) would be your own personal testing and experience.
Different online manufacturers have different return and refund policies with different costs involved and this may be an important part of your personal value equation (the things that are most important and valuable to you in a mattress purchase) when you are buying a mattress online so I would make sure that you check their websites or talk to each of them that you are considering to make sure you are clear on what their return policy is and any costs involved.
Hope this helps.
Phoenix