Some are very useful. But you’re right, they’re rare. This is my all-time favourite: http://www.lokeshdhakar.com/2007/08/20/an-illustrated-coffee-guide/ Reply
I think you’re being a little generous to the “Useful” camp.
I HAVE seen good ones. Honestly. I figured 1 out of 100 is pretty accurate.
Some are very useful. But you’re right, they’re rare. This is my all-time favourite: http://www.lokeshdhakar.com/2007/08/20/an-illustrated-coffee-guide/