I liked Things Past a lot... But one odd thing is Garak being quite ungarakky. He doesn't do much in the episode, pickpocketing one guard and hacking into the computer for relatively useless information, that's all, and he gets off only one or two memorable lines. He's a lot less useful and less snarky than he usually is, which leads me to wonder if the part was originally written for Chief O'Brien or Dax (presumably with Kira in place of where Dax was in the eventual episode) before they figured Garak was always a good thing to have in your episode.