Just finished watching it. And, I agree, todbot--it sure didn't feel like a series finale. Perfectly good last show of a season, but as the conclusion to the series?
Anyway, I also agree MattJohnson, that the scene of Silas talking to God during the thunderstorm didn't work as well as it could have. This was mainly because Silas got all petulant, and Ian McShane seemed embarrassed by it. All in all, Silas has devolved into total jerkdom from being flawed but still showing signs of the greatness that made G choose him.
You know what I didn't get during the last couple or three episodes? The reverend's decision to help Jack and the uncle. I got that he was disappointed with Silas, but I really found it hard to believe that he'd throw his lot in with William and Jack, even if only to help David. I was pleased that he got to be God at the end, though, or, rather, I would have been if the show were continuing, since I would have been sorry to see the last of Kareem Sayid.
A pity this show isn't coming back. It had many faults, but at least it was a little different from the norm. If nothing else, the language was more interesting to hear.