Hi lilac2,
Based on the stores and manufacturers you’ve visited you’ve probably seen this already but the better options and possibilities I’m aware of in the Trenton/Philadelphia/Wilmington areas are listed in post #4 here. As you’ve seen … mattress factories can be very dusty places when foam is being cut and are nothing like mattress showrooms. What you’ve seen is fairly typical.
As you know from reading this site I would generally suggest avoiding major brands. If you do decide to go in that direction then the specs you would need to identify any weak links of a mattress and make meaningful comparisons with other mattresses are in this article and the guidelines I would use for assessing foam quality/density are in post #4 here.
I would need to know the rest of the specs (making sure they add up to the thickness of the mattress) to make any meaningful comments about the mattress. It would depend on the thickness and density of the foam layers that are missing in the specs you provided but in most cases you will find that with major brands they either don’t meet the minimum guidelines I would suggest or if they do then the mattress wouldn’t compete well with other mattresses in the same price range that use the same or better quality materials made by smaller manufacturers.
Phoenix