Over a certain percentage, I bite into chocolate and it just sucks all the moisture out of my mouth and is just terrible bitterness. I think 86% was the last one I tried, but even 50% is getting to be too bitter for me. I was always super sensitive to bitter compounds as a kid, though, so that may make sense. I do actually like black coffee of some beans/roasts, but it doesn't have nearly as much bitterness.