Hi madinsomniax,
This would depend on what you mean by a “sample”. If it is a full topper and you are lying on it in the same position as you would when you are asleep then it would be a fair test. if it is only a sample and the pressure distribution is different from what it would be in your normal sleeping positions then it wouldn’t be an accurate test. a mattress protector, pad, or topper can certainly have an effect on a topper below it and reduce the ability of the latex to conform to your body to different degrees (depending on its thickness, firmness, and on how stretchable it it).
Yes … 19 ILD blended Talalay in the same thickness with one manufacturer will be very similar to 19 ILD Talalay with another although they may not share the same firmness ratings. Different covers will be the biggest variable in how they compare.
This seems to indicate that the Talalay they are selling is 100% natural yes rather than a blend of natural and synthetic. You can read about the differences between 100% natural Talalay and blended Talalay in post #2 here.
Yes … Puralux is blended Dunlop. I have had different feedback about the actual blend but it is probably between 50/50 and 20/80 (NR/SBR). You can read more about the different types of latex in post #6 here.
Only you can really know this because firmness and softness is subjective and relative to the individual. it would be firmer than 25 ILD Talalay though for anyone who compressed the layer more than 25% (which would almost always be the case with a topper) and for most people would probably feel closer to 28 ILD Talalay than it was to 24 ILD Talalay.
As a group I would say so yes and you have identified the differences between them accurately.
Natural Sense is 100% natural Dunlop which would be very similar to other 100% natural Dunlop toppers. They are sourced in Sri Lanka as far as I know (same country but a different supplier as Latex Green which is a popular source). I don’t see anywhere on their site which says they are imported from Europe but of course I may have missed it. Either way … it’s 100% natural Dunlop which is a good quality material. A forum search on foamorder will bring up more comments about them and I have found Alan there to be knowledgeable and helpful in my conversations with him.
While there are no “guarantees” of course … using the guidelines in combination with any personal testing you have done and conversations with each manufacturer can put the odds of choosing a suitable topper much more in your favor.
Phoenix