Has a "clumpy" feeling to it, as if the the corrugation separates in clumps as I lay on it. I only weigh 165# and think the "stems" (for a lack of a better word") sticking up are too tall and skinny. I replaced another topper that I had for 7 years that was an egg-crate type but the "stems" were a little shorter, rounder and thicker so didn't separate. It was extremely comfortable but was beginning to wear out, and bought this one after I couldn't find a similar replacement. 
This one is not very comfortable for me.