Have to agree there of course. MC21 carbs are a breeze to work on. I always used to have a quick groan when I needed to change the needle, or move a clip on my 28 race bike. Carbs off, pull 'em to pieces, blah blah blah. Not exactly something you'd want to do half way through qualifying or something. MC21 much quicker. Whip off the tank, yank off the cover and you're straight in there.

Proper PJ/PWK carbs are even better. If you're lazy you can even change a needle without pulling the tank off.