Three Things I Dug:
The Line About the Lighthouse: I've enjoyed most of the in-jokes the writers have slipped into some of scripts (last season's Hurley/Miles wink-wink debate on how convoluted things had gotten comes to mind). So, in an episode that is almost certainly going to polarize the show's hard-core fans, I'll dredge up goodness wherever I can. And, Jack's "how come we've never seen that before?" line when he and Hurley finally reached the lighthouse tickled me a bit. I'm willing to bet that Jack spoke that line just ahead of the 12 million people watching at home who had the exact same reaction.
The Heel Team: I'm...liking the bad guys, so far. In an epic war of good vs. evil, I'll take Dark Locke, Killa Claire and the young Ben-shootin', POW-torturing version of Sayid any day of the week.
Three Things I Didn't Dig:
The Lost Will: The "Claire Littleton" revelation in the alternate timeline couldn't possibly have been more contrived. Jack's mom couldn't find her deceased husband's will? Fine. It's silly, but, whatever. Then, after finding the will, she's surprised to find the name of his illegitimate daughter (and Jack's half-sister) in it? She'd NEVER seen her husband's will before that very moment? Really? Mrs. Bootleg and I had a trust written up five years ago. She checks it WEEKLY to make sure I've haven't tried to slip in the names of any unknown kids or well-meaning strippers.
The Rest of the Lighthouse: The phantom mirrors were bad enough. Then, we got Jack's inexplicable overreaction to seeing his childhood home in said mirrors. THAT'S the image that drives Dr. Jack over the edge? For six seasons, he's been the man of reason and rational thought whose practical belief system has been tested and tortured. So, a picture of his house drives him to wanton vandalism and screaming? And, later at the lighthouse, what was with Jacob's cold-ass diss of Hurley? ("Some people will do what they're told from the back of a cab, some need to look out at the ocean".) Damn, son.
Jin's Lie: I must be missing something obvious, but why did Jin recant his story to Claire about Kate and Aaron? Jin was just a few feet away from Claire when she did that bad, bad thing with her ax. She clearly stated her history and past encounters with the (other) Others -- even if some/most of it was just Claire's paranoia talking -- so what did Jin hope to achieve by intentionally directing her back to the Temple?
The Verdict: I'm not even going to get into this episode's biggest development, other than to say this -- if you're going to introduce a new character out of the blue, especially a child, then you damn sure better not write him as such a petulant ass from the get-go. The intermittent slivers of Claire-gone-crazy kept this one afloat, but it's time to f*****g do something, Lost. Anything.