This mattress is great and arrived super fast!  I love that it comes packaged in a box for easy transport.  Can easily move it to the location you want it, then open it up there.  We took it to our cabin.  We opened it up, plopped it on the bed (last pic), and then had to leave, so I really don’t know how long it took to expand.  But when we came back 6 days later, it was perfect.  There was absolutely no smell at all.  I would say it’s soft, but firm.  You don’t sink down like other foam mattresses do sometimes.  I was worried it would be too soft, but it’s not.  We measured it, and it’s just a little shy of 10” (like 9 38”).  I’m very happy with this mattress and wouldn’t hesitate to order another  in the future.