One of my favorites series, and I loved the last episode. I get that it wasn't for everyone, but it was the perfect ending for me. Yeah it left a bunch of threads open, but that was kind of the show's MO for years (polar bear anyone?). But the cast got to live real life and the show at once with that final reunion and reminiscing on what they all went through together. And I wasn't confused or "lost" on the whole purgatory thing, which made it easier.
The funny thing on through the looking glass, I don't remember being that shocked? I didn't watch in its original run, after a few years G4 showed four episodes every Thursday night, and that's how I got through it. And I had seen somewhere that there was a season off the island, so maybe that's why it didn't shock me. Was still great though.
Maybe I'll go back and watch it all at some point, might be a fun exercise.