I originally reviewed my Purple mattress after a few days of sleeping on it and was not horribly impressed. I still had back pain and missed the feel of my old mattress. My wife was also still using a 1" memory foam mattress on top of the Purple mattress because the Purple mattress was not soft enough for her. To me, that seemed like it was defeating the purpose of having a new mattress. Why would I buy a new mattress so that my wife could essentially bypass the selling feature of the new mattress by using the same memory foam pad on the new mattress as she used on the old? As an experiment, after about 30 days of sleeping on the Purple mattress, I switched back to my old mattress (a very expensive one with air bladders that allows you to set a number independently on both sides of the bed related to how firm you want the mattress). At the onset of this experiment,, the "old" mattress just did not feel right. Apparently, I was indeed becoming used to the Purple mattress and found myself missing it as I laid down the first night on my old mattress. While I mentioned I initially felt as if the Purple mattress was too stiff compared to my previous mattress, I now found myself complaining that my old mattress was too firm. It did not seem to cradle my body the same way. As I mentioned, I was less than impressed with the Purple mattress initially. Based on the reviews and videos, I expected something magical. Magical it was not. When I returned back to my old mattress, it was with the intent of staying with it and returning the Purple mattress. After all, if the Purple mattress really was no better than my previous mattress, why keep it and pay for a mattress that I am not using or offers no clear benefit over my previous mattress. There is a full 100 days to try it out, but I figured, why wait that long? I have also seen feedback from Purple to some of the negative reviews encouraging people to sleep on the mattress for at least 30 days. When I read those, I tried to figure out what the big deal would be? What would change after 30 days that did not change after 20 or 10, or wouldn't change after 40 or 50? The first impression was important, and I was less than impressed. Anyway, getting back to my "which mattress is actually better" experiment... I am somewhat embarrassed to admit that the experiment lasted a total of one whole evening. After switching back to my old mattress, I woke up several times in the evening with back pain and, as I am writing this review in the late afternoon, my back still hurts. The icing on the cake was when my wife told me she now hated our old mattress (the mattress she used to absolutely love) and to put the Purple mattress back. She was originally wishy-washy on which mattress to keep. She did not hate the Purple mattress, but also did not think it was anything special... until she went back to sleeping on the old mattress, which gave her some significant back and hip pain. With that being said, I am indeed keeping my Purple mattress without any regrets and wish this mattress would have been available back when I spent about five to six times as much for the mattress I currently own. One positive thing that I must mention as well is that neither my wife nor myself have awoken in the middle of the night in a pool of sweat like we used to on our old mattress. The Purple mattress does indeed help keep us cool when sleeping, which was something I did notice right away. For what it's worth, I kind of wish Purple would sell the purple polymer matrix alone so it could be added over the top of an existing bed. I am not sure if that would work, and I doubt that Purple would want to do that as the bed is engineered to work with the foam layers it has, but I would have been willing to try it. I also have a split king adjustable frame, yet Purple does not offer such an option, so when I raise up my part of the bed, it elevates part of my wife's side unevenly, which means we must raise both sides of our bed together (which never happens) or I must be a little less aggressive in how I adjust my side of the bed. Compared to our previous mattress, the Purple mattress is also a lot thinner, which reduced the height of our bed. This has taken some getting used to for my wife. (As for me, I did not notice or care as much.) Considering how heavy this mattress is, I do not know I would actually want it to be much thicker as I would need a lot more friends to help me move it. Maybe that would be another suggestion too... Put some handles or something on it. Not that we move the mattress often, but when you do, it is large, heavy, bulky, and cumbersome. (Not sure how to add handles to a foam mattress, but then again, I'm not the bedding engineer like the gurus at Purple.) For those reasons, and the initial hesitancy I had when first trying out the bed, I had to give four (not five) stars. For what it's worth, my 10 year old daughter loved the mattress from day one and wanted it for herself when I too