In reply to Offwidth:
Don't want to quibble over grades but surely with MFB it all depends upon the start. I have bad memories of that lower crack (I guess you'd love it) so always avoid it by going up the wall to the right or walking round. Above that it's just lovely clean, open climbing, but with a bit of a sting on the final buttress.
I don't doubt that Crescent climb is harder but if it is anything like Crescent Slabs, I won't be soloing it - too much wet rock, vegetation and unstable ground for my liking.
Certainly enjoyed Corvus, but all I remember is the hand traverse section.
Not done the two on Dow Crag, but it's got me thinking !