The mattress is great. It helps a lot with my back pain problems. The reason why its 4 stars is because after 3 months, the mattress sinks a bit on one side. I definitely sleep more on that side and sinking is expected. But sinking after 3 months is quite fast. I'm 158 lbs and 5'11 so I'm no where in the overweight area. Oh, it also took forever to ship. It's like 8 weeks shipping time. But that's not the mattress fault so I won't take a star off it.