Via the Kitchn, here’s a Wall Street Journal piece that wonders if cacao percentages have gotten too high to be tolerable.
I’ve tried a few 100% cacao bars and generally find them inedible. In fact, I like to finish my chocolate tastings on a 100% bar, just to underscore that higher doesn’t necessarily mean tastier.
On the other hand, Michel Cluizel’s Cacaoforte truffle, made from his 99% cacao, is one of my favorites. I’m sure the addition of cream helps.
I personally prefer mild dark chocolate or milk chocolate with high cocoa content. Of course it depends on the manufacturer, but usually 85% is too dark for me.