Hi techmattr,
As you know the Dynasty mattresses are made in China which means that the quality/durability of the materials can be more uncertain, inconsistent, and variable than materials or mattresses that are made in North America and it’s durability could also be affected by any fillers that are used in the foam or how long the mattress was compressed during shipping and storage (see post #6 here). You can read more about Dynasty in posts #3 and #4 here and a forum search on dynasty (you can just click the link) will bring up more information and feedback about them as well.
There is more information in post #2 here about the different ways to choose a mattress (either locally or online) that is the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for that are involved in each of them.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more meaningful quality/value comparisons between mattresses.
I would especially keep in mind that if the Dynasty mattress doesn’t work out as well as you hoped for in terms of PPP and you don’t sleep well on it that there can be some significant shipping costs involved to return it so with all the many uncertainties involved in purchasing a Dynasty mattress it would be a higher risk choice than many other mattresses that are available to you.
In terms of the quality of the materials, the foam densities that they list (the top two memory foam layers) appear to be good quality materials at least on paper but with Chinese manufacturers that may not be as consistent or that use fillers in their foam or that are compressed for long periods of time then their densities may not always reflect the quality and durability of the materials. I would also want to know the quality/density of the polyfoam layers in the mattress as well.
You may have read this already but just in case you haven’t … the first place I would start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and know how and why to avoid the worst ones (so hopefully you won’t end up repeating your previous experience once again).
I would also avoid all of the major brands or any mattress where you can’t confirm the quality and durability of the materials inside it (see the guidelines here).
If you are comfortable with an online purchase then the tutorial post includes several links to some of the better online choices I’m aware of (in the optional online step) and post #4 here also includes several links to some of the better value online options that are in lower budget ranges as well.
If you let me know your city or zip code I’d also be happy to let you know about any of the better options or possibilities I’m aware of in your area as well.
I would be very cautious about using other people’s experiences or reviews on a mattress (either positive or negative) as a reliable source of information or guidance about how you will feel on the same mattress or how suitable or how durable a mattress may be for you and in many cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person may be completely unsuitable for someone else to sleep on (see post #13 here). Their Amazon reviews certainly reflect this. In the end the only reliable way to know with any certainty whether a mattress is a good match for you would be based on your own personal testing or actual sleeping experience.
Phoenix