Hi Pooswa,
Besides of course testing any mattress for PPP (Pressure relief, Posture and alignment, and Personal preferences) I would want to know the type of latex that is in the mattress and whether it is blended or 100% natural. There is more about the different types of latex in this article.
I would want to know the thickness of each layer and the density of the memory foam layers and the density of the polyfoam layers. There is more about memory foam in this article and in post #8 here which may be helpful.
There are many brands that use talalay latex in their mattresses but Pure Latex Bliss is one brand that makes all Talalay latex mattresses that are fairly widely available. Bear in mind though that these tend to use softer Talalay layers on top than some other manufacturers. They have a retail outlet finder on their site here. Restonic also makes all Talalay latex mattresses in their health Rest line, Spring Air also makes some all Talalay latex mattresses and Jamison does as well. There are many more but it’s much easier to call retailers in your area and ask if they carry any “all talalay latex” mattresses because in many cases a manufacturer may make them in one area of the country and not another.
Tempurpedic makes 15 different memory foam mattresses and all of them feel different. I think what he meant is that the memory foam he uses (5 lb) is the equivalent quality to the 5.3 lb memory foam that Tempurpedic uses but this doesn’t mean that they would feel the same as any of the Tempurpedic mattresses because two different types of memory foam even of the same quality/density can feel and perform very differently and the type and thickness of the memory foam layers along with the firmness of the polyfoam support layers can all have a big effect on how a memory foam mattress feels and performs.
This is a latex hybrid with latex in the top layers and polyfoam in the support layers. I don’t know the type of latex, the thickness of the latex layer, or the quality/density of the polyfoam they use in the base layer and I would certainly want to know this. They are also not comparable to an all latex mattress but would be comparable to other latex hybrid mattresses that used similar materials and layering. A latex/polyfoam hybrid is much less costly than an all latex mattress (polyfoam is a much lower cost material than latex)
Hope this helps … and I am a few days behind in many of the phone calls I need to make (some over a week behind) so I’ll leave you to make the call and ask the questions because now that you know the questions the answers will be very easy to find 
Phoenix