Hi pmdva,
Welcome to the Mattress Forum!
The first “rule” of buying a mattress is that your own personal experience always “trumps” theory" so while they may be right based on “theory” or on the “averages” of other customers that are similar to you in terms of their body type and sleeping positions … there will always be exceptions where a mattress that wouldn’t work as well for “most” people that are similar to you may be the best choice for “some” people that don’t fit the averages. The most reliable way to know whether a 6" mattress is a better “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) than a 9" mattress is based on your own careful testing and personal experience … hopefully using the testing guidelines that are linked in step 4 of the mattress shopping tutorial
If you can’t compare two mattresses in person or are uncertain about your choice then the exchange/return policy would become a more important part of the “value” of your purchase so you can reduce the risk of making a purchase that doesn’t turn out as well as you hoped for. There is more about the different ways to choose a mattress (online or locally) that can help you assess and minimize the risks of each of them in post #2 here and 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 different mattresses.
I would encourage you to try both so that you can decide on which one seems to be a better choice for you based on your own personal experience or alternatively make sure you have good return/exchange options after a purchase if you can’t compare both of them in person.
I would treat the choice between Talalay and Dunlop as a preference choice not as a “better/worse” choice. There is more about the differences between them in post #7 here. I would also keep in mind that there are other very similar component latex mattress options besides Savvy Rest that are available to you that use very similar materials that are in lower budget ranges as well so the “premium” for a single layer of Talalay latex or even all Talalay latex layers (blended or 100% natural) won’t be as high. For people who strongly prefer Talalay latex in either the top layer or in all the layers (and there would be many) it would certainly be “worth it” and for those who prefer Dunlop it wouldn’t.
The tutorial also includes a link to a list of the members here that sell mattresses online (in the optional online step) that compete well with the best in the industry in terms of their quality, value, service, and transparency. Many of them make latex and latex hybrid mattresses (including component latex mattresses that are very similar to Savvy Rest) that use different types and blends of latex that have a range of different designs, options, features, return and exchange policies, and prices that you can use as a reference point for comparing “value” based on the parts of your personal value equation that are most important to you.
IMO it would be worth a trip to help you make the “best” choice since you will be sleeping on your mattress for many years and a little time spend now can make a big difference in how you sleep for the next decade. If you let me know your city or zip code I’d also be happy to let you know about any of the better local options or possibilities I’m aware of as well.
While the odds are probably higher that you may do better with three layers than with two (and a three layer mattress also have more options to customize the feel and performance of the mattress as well either with rearranging or exchanging layers) … I would always keep in mind nobody else can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved for anyone to be able to predict which combination of layers you will do best with based on specs or “theory at a distance” that can be more reliable than your own personal testing or sleeping experience.
Phoenix