Hi quixote,
This would depend on which mattresses are included in your lists of finalists.
If your final list is between the Dunlop models and their 100% natural Talalay models then the choice would depend on any difference in how well each mattress matched your specific needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and on whether you preferred the “feel” of Talalay vs Dunlop and whether any difference was worth the difference in cost to you. You can read a little more about the different types of latex (including organic Dunlop) in post #6 here. Both of these are high quality materials and would have little difference in terms of durability.
I think you are clear about the benefits of a layered latex mattress and some of the benefits of this approach vs a “finished mattress”.
The other benefit is that the top layers of a mattress will tend to soften and break down faster than the deeper layers so this design also allows you to just replace a single layer instead of the entire mattress if that becomes necessary.
You can read more about layers shifting in post #2 here.
Post #1 here which includes the basic guidelines I suggest when you are mattress shopping also includes a link to some of the online members here that also offer a range of component latex mattresses with a similar or even the same design (three 3" layers with a wool quilted cover) that offer a larger choice of which type of latex you prefer which in some cases includes blended Talalay which is also a very high quality material but lower cost. I would encourage you to make some good “value comparisons” so that you are comfortable with the higher prices that may be involved with a purchase from Savvy Rest.
There may also be some other options available locally depending on where you live and if you let me know your city or zip I’d be happy to let you know of any options I’m aware of that are close to you.
This is reversed from the more usual order and there are very few people who would prefer this (athough each person can have very different preferences). Are you sure the layers weren’t the other way around (most people would be quite uncomfortable with firm latex on top). I would tend to avoid soft latex on the bottom because it may increase the risk of alignment issues and it may be worth considering using medium or firmer which is a more usual design and because the deepest layer of the mattress has the least effect on how it “feels” for most people so there is little reason to use soft on the bottom.
IMO … Savvy Rest itself is a reliable company that has been in business for along time and has good quality products that are certainly better “value” than many mainstream mattresses that are sold in the mainstream industry … they are just in a more premium price range compared to other similar mattresses for those who are aware of other lower cost alternatives for similar component designs.
A forum search on Savvy Rest (you can just click this) will also bring up many more posts you can scan through with more comments and feedback about them.
Phoenix