Hi 2manybeds,
Just in case you haven’t read it yet … I would make sure you’ve read the tutorial post here which has all the basic information, steps, and guidelines that can help you make the best possible choice … and avoid the worst ones.
As you will see from the guidelines here … I would avoid major brands (such as Simmons) or any mattress that doesn’t disclose the quality of the materials inside them because there is no way to identify any weak links in a mattress or make meaningful comparisons with other mattresses. In most cases the major brands use some low quality materials in the upper layers of their mattresses that make them a risky choice in terms of durability and the useful life of the mattress. To their credit … Saatva provides all the information you need to make an informed choice in terms of the quality/durability of their materials. You can read a detailed analysis of Saatva mattress in this thread and a forum search on Saatva (you can just click this) will bring up more posts and feedback about them as well and I would certainly consider them to be a better quality/value choice than a Beautyrest Black or most other major brand mattresses if my choice was limited to these two mattresses. Of course the quality of the materials has little to do with how a mattress feels because you can’t “feel” the quality of the materials and lower quality materials can feel the same as higher quality more durable materials … at least for a little while.
There are too many variables, unknowns, and individual preferences to use a formula or “theory at a distance” to predict how well any mattress will match your specific needs and preferences in terms of PPP (see mattress firmness/comfort levels in post #2 here) and each manufacturers comfort scale is very subjective and can be different from each other (there is no “comfort standard” in the industry). Post #2 here has more information that may be helpful if you choose a mattress that is too firm but assuming you still have the option of a refund after a mattress exchange (I don’t know their policy on this) then there would be little harm or risk in trying the softer version from Saatva. The tutorial post will give you the steps and guidelines to use if you want to start over again to find a mattress that may be more suitable for you but if it was me it would depend on the return options you would have after an exchange or whether you wanted to spend the time to do additional research into buying a different mattress either locally or online.
Phoenix