The Prana was 2" - 10 ILD.
The Sleep EZ softest is either 1.4" 22-24 ILD or 2.8" 22-24 ILD, depending on which model you get.
The FloBeds convoluted topper is 2".
I am 6'2", 160 lb and my wife is smaller than I am. I was originally thinking the Sleep EZ that had three 2.8" cores would be better because we could interchange all the layers. But since I like a firmer mattress, I am wondering if the Sleep EZ with two 2.8" cores with the 1.4" core on top would be better so I could get the soft top, but firmer support system. My wife, who likes the softer mattresses could do a soft on top and in the middle and then something firmer on the bottom. Hmmm...