I must have a firm mattress that also doesnt create pressure point pain.  I was sooo sceptical given the price but I read and reread what people said about this mattress, weighed all the pros and cons as it pertained to my sleep needs and ordered this mattress.
Yes its firm but as I alluded to before there are no pressure points leading to discomfort or pain.
Im delighted with my purchase.
I purchased it long before I set it up but Ive been sleeping on it now for a couple of months and I am completely delighted with this mattress! BTW the edges do not sink or break down as a result of sitting on the edge. Granted this only a few months of use but I feel confident its going to hold up. If for some reason it doesnt I will let you know that too!