In reply to duncan: I guess that's where our grading system doesn't show much - E5? E6?
Alex Honnold soloed the Moonlight Buttress, which would probably get E6, but it's not an E6 solo route - it's a fully protected crack - at around F7c! (And miles up in the air!) So that's kind of like soloing Cave Route Left Hand at Goredale (admittedly that's F7c+ for the pendants, but you get the point), not like soloing Piece of Mind at the Roaches (not that I'd want to fall off either, but Cave Route is way harder).
An amazing effort.