Hi spkimball,
There are probably many better options than the Pranasleep line and you can see some comments about them in post #3 here and in this thread. A forum search on Pranasleep (you can just click this) will bring up more comments as well.
The Asana 5 has 2" of Talalay latex over a polyfoam base layer and they also tend to use a thick quilting layer on top which would be the weak link of the mattress. I would want to know the thickness and density of the quilting layer but as you can see in the linked thread they don’t disclose this. They are not particularly good value for the design and the thicker layers of polyfoam not only can take away from the “feel” of latex, they would also be fairly risky because polyfoam will soften and compress much more quickly than latex and the loss of comfort and support that comes from foam softening isn’t covered by warranty.
I would tend to look for other options that are similar in terms of materials but have better quality/value.
Phoenix