Hi BBF,
I would keep in mind that the most effective way to choose the firmness of a mattress is with your own personal testing on the mattress or if that isn’t possible then to use your local testing on similar mattresses as a reference point in combination with more detailed conversations with the manufacturer on the phone.
Perceptions of softness and firmness are subjective and each person’s experience on a mattress can be very different depending on many factors so each person’s experience on a mattress is unique (see mattress firmness/comfort levels in post #2 here). I would be very cautious about assuming that someone else’s experience on a mattress will be similar to yours or about using anyone else’s experience on a mattress as a guideline for your purchase.
One of the features of the Alexis is that there are two layers that can be exchanged so if you need to do any fine tuning to the mattress after a purchase either for pressure relief, support, or personal preference reasons based on your actual experience that there are good options available to do so.
Edge support is not an issue for most people when it comes to foam mattresses unless they sit on the very edge of the mattress or sleep with the heavier parts of their body on the very outside edge (which isn’t the norm for most people) and the mattress is in the softer range. You can read more about edge support in post #33 here. With a mattress that has edge support it’s also important to make sure that the method used is a high quality material so that the edge support materials are not lower quality and don’t soften or break down faster than the materials used in the inner part of the mattress because edge support can sometimes be a way to reduce the cost of a mattress by using lower quality/durability materials (such as polyfoam) to replace the latex.
Phoenix