Hi anon,
They would be similar but not necessarily the same. Latex ILD’s are not exact and this is especially the case with Dunlop which has a wider ILD range than Talalay. Because of this … even two different Savvy Rest mattresses with the same ratings may be different from each other. Fortunately … most people are also not so sensitive to smaller variations in ILD ranges.
You can see the Savvy Rest ILD range for their different materials in post #7 here which have a slightly wider range than the SleepEz ILD range listed on their site. If the layers are the same type of latex and had the same ILD rating … I think most people (including several forum members who have tried both) would consider them very close.
There are some general guidelines for body type here and for sleeping positions here along with the effects of different types of layering here but these are meant more to give you a sense of the different factors involved in making a choice and not as specific suggestions for any individual. For specific suggestions, it’s always better to go by your own personal testing results or to talk with the manufacturer directly because they have much more detailed knowledge of the specifics of all the layers, components, and options they have available and how they work together and also have the benefit of a large customer base that they can use as a reference point. In general though … I would tend towards the same or very similar firmness ratings as you tested even though the soft/medium/firm ratings may be slightly different between different manufacturers or different layers. For most people this would not be an issue.
You can also see a comparison between their covers in post #3 here which would also make a difference.
the organic line gives you a choice of either organic Dunlop or 100% natural Talalay while the natural line gives you a choice between 100% natural Dunlop and blended Talalay. In any Dunlop layers of the same ILD … the difference between the 100% natural Dunlop and the organic Dunlop would be negligible and I doubt that anyone could feel a difference.
The difference between 100% natural Talalay and blended Talalay would be less than the difference between Dunlop and Talalay but in a comparison between the same ILD’s the blended Talalay would be a little softer, more pressure relieving, and a little less resilient and elastic. In a 2 or 3 inch layer with other layers below it I doubt most people would feel much difference in a blind comparison but comparing mattresses that had say 9" of each type of Talalay, I think that most people would fdeel some difference because of the higher compression modulus (gets firmer faster) and higher resilience and elasticity of the 100% natural Talalay vs the blended version. There will also be some small (but again not that significant in terms of feel) differences between Talalay from different manufacturers.
Hope this helps.
Phoenix