Okay, I think we can confirm that the dimensional portals between Earth-1 and Earth-38 are displaced through time. When Barry and Cisco came to recruit Kara's help against the Dominators, it was just after Thanksgiving on her Earth. But Oliver's comments at the Christmas party peg the Dominator invasion as coming about a week before Christmas on Earth-1. So the rift was displaced about three weeks backward.
And we also know the invasion happened in 2016, according to Sara in the preceding Legends episode. So if it happened in the third week of December 2016, that means that either the president who was killed was a lame duck anyway and his VP is only going to be acting POTUS for a month, or he was a re-elected incumbent about to start his second term. I guess that depends on whether we see the replacement president again in the Arrowverse.
This one didn't go the way I expected. I thought we'd surely get a reveal of who Prometheus was in the closing minutes. As it was, the ending was a bit understated and jumped around from one thing to another. But it was interesting to get flashbacks to the early first season.
Something bugs me about Curtis and Paul -- I don't think we've ever seen them kiss or show any physical affection to each other. The lesbian characters on CW shows get to make out on camera, so I wonder if the network has a double standard where gay male characters are concerned. If so, maybe that's why Curtis and Paul don't seem to show much chemistry, always seeming to be at arm's length physically and emotionally. I've never really been sold on their relationship. (I was going to say they seemed stiff together, but then I realized there's an innuendo there that's kind of the opposite of what I mean...)
Also, where did Evelyn disappear to after her big outing as the traitor? There should've been some followup on that. And I'm not sure what purpose it served for her to reveal herself at that point in Prometheus's plan, since they just retreated after that and it didn't really accomplish anything. Maybe it wasn't part of the plan -- maybe she had to reveal herself to save Prometheus from Wild Dog. But everything else was so meticulously arranged that that's hard to believe.
And whatever happened to the reveal that Prometheus had to be someone with the SCPD in order to get the Hood's old arrows out of evidence? Was that just a red herring to make us suspect Lance? It'd be kind of a cheat if it turned out to be untrue now.
). Oh and the Waverider coming to the rescue ala the Millenium Falcon in ANH, awesome! 
