First of all, let me just say that I have only had this mattress for about a week. I will continue to update this review as time goes on, but for now these are my preliminary thoughts. I am going to include the background of how and why I decided on this mattress because I think there may be some information that is helpful to you in your own journey. Feel free to scroll through to the actual product review if you don't want to read all of that nonsense. A little background: The mattress I had was a full sized very plush pillowtop mattress that was probably 15 years old. It had started to droop in the middle a few years ago but I just dealt with it. As a result, I developed a lot of neck and back problems. With that in mind, as well as my budget, I set off to find a replacement. I haven't bought a mattress in quite some time so there were a lot of new products on the market that I needed to consider; Memoryfoam, hybrid mattresses, Eurotop, pillowtop, etc. If you are anything like me, this is probably a time consuming process and ordering online is always a roll of the dice. I started with Amazon since it is the easiest way to explore options and read reviews. I thought I MIGHT want a memory foam mattress because I wanted something firmer yet still comfortable. I checked out some product reviews then proceeded over to Youtube to get a more visual perspective with some additional feedback on the actual products I was considering. After that, I visited sleeplikethedead.com which is an extremely handy website. Not only do they offer comparisons of mattress types, but they also give you data tables showing where the most satisfied range of consumers are among mattress types, brands, and cost categories. I was surprised to find that the most satisfied customers were actually on mattresses that were in the 500 dollar price range and with brands such as Sleep Master. After all of that, and with an idea in mind, I set out into my local community to test-drive some mattresses. So if you are apprehensive about a cheaper mattress, check out that site. I am 5'6 about 140 pounds and I am typically a side and back sleeper (stomach sleeper when I am restless). This, of course, made my quest that much more daunting. I started out with liking the idea of memoryfoam but once I started laying on the memoryfoam mattresses I found that it was nearly impossible to roll over or change positions. They provide excellent support for back sleepers and are very comfy, but if I can't move around I get a little antsy. So that was a no-go for me. Next up was the hybrid mattresses (like this one). I found that I really liked the eurotop mattresses because of the fact that they are just enough cushion at the top with ample amount of support. Unfortunately, all that my local dealers had were high-end fancy mattresses and my budget was simply not anywhere near that ballpark... especially after what I read on SLTD.com. I don't know how much credibility there is to this assumption, but I got the feeling that a thinner mattress might break down faster, and not offer as much support. BUT that is just the impression that I got. Others are welcome to comment and offer their feedback but I decided I wanted at least a 12 inch mattress... especially if it was going to have coils. So I returned home where I exhaustively (and maybe a little obsessively) scoured Amazon for different mattresses that met my criteria. I saw this mattress and decided to go for it. It received favorable reviews here and on several other sites so for the price mark I decided it would be a good introduction to this type of mattress. So far, I think this is the type of mattress for me. That said, lets move on to the review. The Mattress: Many of these hybrid mattresses are classified as medium-firm, which makes sense when you think about how they are constructed: firm springs on the bottom, with soft memoryfoam on the top. A happy medium for those who want pressure point support but also don't want to be sucked into quicksand. After my first week of using this mattress I will say that this particular mattress is firm. I have noticed that it has started to break in a little so I am wondering if maybe that just isn't how it is with new foam mattresses. It has also been very cold here and I know that foam tends to be firmer when it is cold. I have read several other reviews that say the same thing. For me, personally this mattress is still comfortable. I have sciatica and being able to lay flat and still feel like my pressure points are relieved is a big deal. I should also add that my hips are often the biggest hindrance to side sleeping comfortable as they are a bit wider than the rest of my body. I also have broad shoulders. Either way, I sleep very well on this mattress and most of the time I can sleep for hours on my side without any discomfort at all. I don't have any more neck pain or stiffness and my sciatica has dramatically improved. I will warn you though, this mattress is firm the first few nights and while I was comfortable, my boyfriend commented jokingly that it was like sleeping on 2x4s. He prefers a much softer mattress though, so that is probably a matter of individual perspective. It would easily be resolved with as little as a 1 or 2 inch mattress topper, if you find it to be particularly unbearable. This mattress arrived coiled up. The instructions indicated that you could cut the tape straps and unroll it onto the surface before cutting the wrap to allow it to inflate. Let me warn you now: THIS MATTRESS WILL BEGIN TO EXPAND AS SOON AS YOU BEGIN TO UNROLL IT. I learned this the hard way because I had to lift this thing onto a 2 foot platform bed and I had to do so quickly as it unexpectedly began to expand in the very small space of my room. It was, however, hilarious in an I Love Lucy sort of way. It is, however, much lighter and easier to manage if you can uncoil it first. There is Off-gassing, but I slept on mine the first night and while I could definitely smell the mattress, I slept through it. Of course, I had also just built a platform bed for it, so my room was delightfully fragrant in the smells of wood stain and mattress-gas. :) It is possible that the reason I slept so well was because I was slightly intoxicated by the fumes. If you are sensitive to smells, this will probably bother you. Another reviewer mentioned that she stuck dryer sheets between the mattress topper and the mattress. This would actually probably work very well to overpower the aroma. That said: I am giving this 4 stars mostly because I don't know YET how firm it will actually be. It is not super firm, but I would definitely initially classify this as a firm mattress. The quality of the mattress is quite nice, and I do expect that it will last for at LEAST 5 years if not longer. Which I think is long enough for a 300 dollar mattress. This is also definitely a Queen sized mattress and within an hour it had fully expanded to 12 inches. I am satisfied with this purchase. Also: It did take a little while for my mattress to arrive. Amazon projected that it would arrive on a Thursday, but it didn't actually arrive until Monday. So beware of that. Otherwise, good luck to you all in your mattress quest.