Hi Petro,
Assuming you decide to pull the trigger … congratulations on your new mattress
@ wookiesleeps,
Based on your comments it certainly seems like your mattress is too firm for you.
As you mentioned … you really have two options which are adding a topper or returning the mattress.
If you do decide to go in the topper direction then post #2 here and the topper guidelines it links to can help you make the best possible topper choice. Because of the differences in your weight … it may also be worth considering a topper that is the same height but a different firmness level on each side.
Post #3 here and the posts it links to have more information about choosing a mattress for higher body weights that may be helpful in choosing a mattress that would be suitable for your husband (or for couples that have a large difference in their body types).
Both the 12 in 1 customizable mattress (that uses 2 lb polyfoam) and the Freedom mattress (that uses synthetic latex) use good quality and durable materials that would be suitable for your husbands weight in terms of durability but when you can’t test a mattress in person then I would make sure that you have a more detailed conversation with a knowledgeable and experienced manufacturer about your comfort choices because they will know more about their own mattresses and be a much more reliable source of guidance about “matching” their mattresses to different body types, sleeping styles, and preferences based on “averages” than anyone else (see mattress firmness/comfort levels in post #2 here).
A soft layer that would be suitable for most body types may be too soft for your husband especially and may be more risky in terms of alignment and it may be worth asking them about adding an additional firmer layer (medium or firm) to your purchase so in addition to the different combinations that are possible with both mattresses you can also experiment with replacing the soft layer with something firmer.
Phoenix