Hi nokry56,
If you can’t test a mattress in person then you would need more detailed conversations with each manufacturer (including any information about mattresses you have tested) to get a sense of which version of each mattress would be most suitable for you (see mattress firmness/comfort levels in post #2 here which is one of the links in the tutorial post here).
I would also make sure you are comfortable with the exchange or return options which may also be an important part of an online purchase if you make a choice that is less than ideal.
It may be difficult to find someone that has tried both because most people would choose either one or the other and even if you could their perceptions may be very different from your own. When you are down to final choices between “good and good” then you will need to rely on your conversations with each manufacturer (including all the information you can provide about similar mattresses you have tested and liked) and your “best judgement” to choose between them.
Phoenix