Hi SallyS,
I think your suggestion to try lots of mattresses is a good one because there is such a wide variety of different mattresses in each category. One “latex” mattress can be very different from the next.
45th Street Bedding doesn’t normally use GOLS certified organic Dunlop in their mattresses but they do have an alternative supplier that has GOLS certified latex available but they consider it to be somewhat of a downgrade compared to their 100% natural Dunlop in terms of feel and performance.
Most latex mattresses don’t have just a solid slab of latex and the same materials that you can use as a topper can be used inside the mattress itself. Whether a latex mattress needs a topper or works perfectly by itself would really depend on the specific design of the mattress and of course on how well it matches the specific needs and preferences of the person themselves.
This may be because you were comparing softer Talalay to firmer Dunlop so the comparison wasn’t “apples to apples”. The firmness of the latex and the specific design of the mattress would make a difference in how it feels and responds to pressure and movement. You can see an example of what I mean and how Dunlop compares to Talalay in an equivalent firmness level in terms of "springiness (resilience) in the video in post #7 here.
Phoenix