After hearing so many good things about Casper I thought I'd give this mattress a try. Turns out the essential is a very firm mattress. I felt a little mislead, as I had read some people saying the firmness was at a 5. Definitely not true! On a scale of 1-10 I would rate the firmness of this mattress at an 8 or higher. And I'm a side sleeper so this just didn't work out for me. I didn't have any issues when laying on my back or stomach while awake, but I sleep on my side. So I kept waking up throughout the night with my shoulders and hips slightly hurting. I would not recommend this mattress for side sleepers. Everything else about the mattress was great. Expanded quickly and fully, has a nice cover on it, and has a fresh, clean smell. No chemical odor. I would give a higher rating if Casper made it more clear that this is a firm mattress in the description.