This is our first memory foam mattress. We received it fairly quickly (less than a week from order) and it arrived well packaged/undamaged (we actually missed UPS delivery and went to pick it up at the facility after hours). We opened the mattress the next morning (not really any odor unless you put your nose right on it - then still very faint to me, and I have a very sensitive nose!) and placed it on top of our old boxspring. You can see from the photo that the mattress size is a couple of inches longer (on both ends) than our standard queen boxspring (photo taken about 22 hours after opening). Mattress at full size measures approx. 61"x 81.5" when I measured at the widest and longest. The mattress was about 7 inches thick right when we opened it and got it straight on the bed; within half an hour it was about 8 inches; about 14 hours later it was about 9.25 inches. We slept on it then, and this morning (when I took the pic) I measured it about 9.5 - 9.75 inches. It is slightly curved along the edges (no distinct "corner" or seams along it like a spring mattress, but seemed pretty even as far as thickness and shape all around. 30 hours and it is now at a full 10 inches, as well as 2-3 inches larger all around than our boxspring, though it still fits within the frame if our wooden sleigh bed. (Our standard queen sheets still accommodate the larger/thicker mattress, too.) Since it is still pretty cold (and we keep our thermostat set at about 65-68 I didn't notice the mattress making me any hotter than usual (we also sleep under a heavyweight down comforter and cotton bedspread, & I do complain about being too warm compared to my husband sometimes, but we were both very comfortable.) Our old spring mattress was very, very badly misshaped and worn out, so our first night on this memory foam was of course a huge improvement. I felt very relaxed and my hips did not hurt from sleeping on my side anymore. I am very satisfied with this purchase because of the low price point, convenience of shipping, and all the basic qualities of a memory foam (antimicrobial, hypoallergenic, dust mite resistant), + a 20 year warranty! (As an added bonus, you get the memory foam pillow. My husband tried it last night, but can't decide it is is too firm/thick for him since he sleeps mainly on his back). Since we only slept on it one night, only time will tell whether the memory foam really helps us sleep better & provides better alignment/support. I did notice a lot less movement (I suppose our bedframe may have still moved a bit) when my husband tossed and turned (whereas it always caused me to be near motion sick every time he did on our old spring mattress). Also, I was expecting from some other reviews that the sides would lack support but I found this to not be the case for me as I get up in the morning. I would agree firmness for this mattress is about 6. It feels very soft/cushy on top but also provides a firm base beneath so that you settle in a little but I don't feel as if I have sunk it and can't move. We also received an email from the seller a few days before arrival which I found helpful with a few tips/info about the mattress, as there are some conflicting comments online and in reviews (such as how after arrival you can wait before opening - some said forever but this seller recommended within 72 hours). I wonder if some of the issues with expanding, odors,etc are due to people not following suggested guidelines? I will definitely update if anything changes from this initial review!