Hi Mickayla,
As GrandmasterJ mentioned (thanks for sharing your experience :)), they are the same manufacturer and both are made by Springfield Mattress which is also an Englander and a King Koil licensee.
The foams are sourced in China and while Dynasty has Certipur certification SilverRest and Springfield don’t (NOTE: both of these are now on the CertiPUR list). Certipur certification gives some assurances that the mattress doesn’t contain harmful substances or emit VOC’s more than the testing limits but doesn’t say anything about the quality of the materials.
A mattress is only as good as the quality of the materials inside it and in my experience some of the SilverRest and Dynasty products may have incorrect descriptions (based on their listed foam densities compared to their shipping weight). You can see some comments about both of them in post #5 here and in post #2 here and a forum search on Silverrest and on Dynasty will bring up more about them as well.
post #6 hereYou can also see a few more comments about memory foam that is sourced from China or Asia and may have been subjected to compression for longer periods of time in .
Phoenix