Hi FloridaMom,
As you mentioned they are both very similar mattresses and the differences between them would really come down to any differences in the type and blend of the latex you choose or have available for each layer, any slight differences in the firmness of each layer, any differences in the cover and quilting material, any differences in their return and exchange policies, and of course any differences in their prices for the specific combination of layers that you end up choosing.
As you know you are certainly looking at some very good quality/value options and I think highly of both of them. Once you are down to finalists that are all choices between “good and good” and none of them have any obvious weak links or lower quality materials in their design and if there are no clear winners between them then you are in the fortunate position that either of them would likely be a suitable choice and post #2 here can help you make a final choice based on your material preferences, your conversations with each of them, their prices, the return/exchange options they have, any additional extras that are part of each purchase, and on “informed best judgement” based on all the other objective, subjective, and intangible parts of your personal value equation that are most important to you.
Phoenix