I like sleeping on firm mattresses and I was worried that this would make my bed too soft. I was pleasantly surprised that this topper supported me and felt like a firm mattress. Yes, the heavier parts of your body "sink in" but they are fully supported and your body stays in perfect alignment while sleeping. I do not think I have ever fallen asleep that quickly, The topper comes in a 29 pound box. I suggest getting someone to help you unwrap it. it quickly unfolds on its own in 20 minutes, but once it is open, it is difficult to move around and position, Because of the added depth of the topper, some fitted sheets will not fully cover the side of the mattress, I am not able to tuck the fitted sheet under the mattress, but everything still stays in place and nothing has moved in the middle of the night, I personally feel that this set with the cover is necessary because it is fitted to the topper and is the only thing that will hold it in place over time. I strongly suggest this topper... everyone in my house is jealous.