I thought the episode was really well done. I didn't even see the Charlie thing coming at the end, which was a nice last scene moment.
I can't decide if I like the way this season they've been focusing entire episodes on one character or group of characters and not showing the other survivors at all. It's good in some ways as it maintains the story flow for an episode, but the other characters (Sayid, Jin, Sun, etc.) seem to be getting lost in the shuffle, which I don't like.