I think you are right, except that Cadbury doesn't meet any of the criteria for the good stuff. Only 35% cocoa solids I think. I have had milk style chocolate with more than that.
For the lovers of old fashioned plain dark, Dr us have brought back a retro box with chocolate cream, mint cream and the mixed fruit cream and Turkish delight for christmas
I've tried 100%. Not as wonderful as I'd hoped. Did finish it, but had the impression of eating spoonfuls of dry cocoa. Not going to retry. Probably better for cooking.