I am not sure who the archangel that Comstock talked about was either, I just assumed he lied as a way to explain the things he saw. Hope my second and probably third play through will fit it all together for me as there are a few things I still don't 100% get. I am still not sure what to make of the very end, like after the credits, that last little scene and also why is there one Elizabeth at the final baptism not wearing a pendant who has her full pinky and doesn't disappear. Booker mistakes her for the Elizabeth he has been with the whole time, then corrects himself. Now I feel like I am missing the glaring obvious. Haha.
I never saw the end coming, I kept trying to figure it out and had some ideas but that wasn't what I thought at all.
I don't know which game I like more, Infinite as you said probably has the greatest ending in video game history, but I actually enjoyed the characters a little more in the original game. Cohen, and Ryan are still my two favorite video game characters ever. I enjoyed the world of Rapture a bit more then Columbia and I loved revisiting it in Infinite. One of my favorite moments in the game. Really I can't pick a favorite between the two, Bioshock and Half Life 2 have shared being my favorite game for many years so I think I will just add this one to the top alongside them.