Did my first run through Crota's End last night with some fellow DBOers. Got close to defeating Crota a few times, but never quite pulled it off. Some quick first thoughts:

I like Crota's End, but I don't think I like it as much as the Vault of Glass.
It is more tightly designed... far less down time. I'm sure some people will prefer the near non-stop action, but I miss the sense of atmosphere and tension that the quieter moments in the VoG create.

There are lots of interesting mechanics at play. I particularly liked the bridge sequence, and the way it forces each player to take "center stage" as the encounter progresses. However I do wish there was some form of challenge that didn't involve combat. The VoG had the long jump down to the Gorgon's lair, the Gorgons themselves, and the jumping puzzle. We'd heard the rumors of a sparrow-chase segment... it's too bad nothing like that made it in to the raid.

Minor complaints aside, I had a lot of fun. Looking forward to giving it another shot!