I agree Zion is the shiz. I don't have such glowing reviews of Iron Messiah though. I thought it was pretty mediocre and I don't remember any 10c. Its pretty funny though, there is lots and lots of killer free climbing at Zion, but nobody does it. People either stick to aid climbing or the two or three publicized free climbs, like IM. But there are so many good Grade IV free routes there if you don't mind some wide cracks and sandy pitches.