Hi albertmills.
Welcome to The Mattress Underground Forum! 
Dunlop has a different “feel” and performance than Talalay and is less lively or springy. You may want to read a bit more about the differences between Talalay and Dunlop in post #7 here.
but your own experience is really the only way to know which one you prefer with any certainty. Some people would notice more of a difference but you will “feel” more of the upper layers than the deeper layers … at least when you first lie on a mattress.
At a glance, neither of the mattresses would raise a red flag in terms of durability as both use good quality materials that should “last at least a decade” if your BMI is not over 30. S&S is thicker uses Dunlop in the comfort layer, cheaper, but the cover is not removable. Malmo is thinner uses Talalay and the cover is removable for those that might want to exchange or replace layers down the road.
Silk & Snow has diversified their offerings since they started in 2017 and they seem to be holding the line. They now offer 3 mattresses and RV and customized constructions.
(12") S&S Organic Mattress you are looking at the following construction:
[indent]Cotton Cover (Organic GOTS Certified ) not zippered
1" Quilt Jooma Wool
0 3/4" Dunlop Latex (D 65 / 14-19 ILD, soft) Organic (sourced from Arpico Latex in Sri Lanka)
1 3/4" Dunlop Latex (D 65 / 14-19 ILD, soft)
8" Pocket coil zoned with edge support (coil count 800 in Queen & 992 in King size)
Firmness: medium firm
Not customizable, Made in Canada
Less expensive[/indent]
(8") Berkeley’s Malmö Hybrid Mattress
[indent]Cotton cover (Organic) Zippered, removable, quilted with Plain-air French wool
2’ Natural Talalay Latex (18 ILD/soft) (sourced from Radium in the Netherlands)
6" pocket coil unit (15 gauge coil count 1,484 in Queen & 1,908 in Kingsize)
Can open the cover to replace/exchange the upper layer. Made in the USA
Firmness: medium firm
More expensive[/indent]
You can see some past comments about Malmo in Post #13 here . Other threads about the Berkeley Ergonomics Malmo vs Oslo where consumers comment about this particular model and about the company itself.
Hopefully, someone who tested or has experience with both mattresses see your post and chime in with their perspective. I’d look again at the personal value equation and what is important to you to make the final choice. My personal experience is that I spent more time comparing my finalists than narrowing down my options.
I look forward to hearing what are the decisive factors in selecting your winner.
Phoenix