I've now seen the crossover twice. I've watched the individual episodes and then I watched them back-to-back. I really enjoyed them, though like others, I did feel that conversation between Clark & Kara at the end could have been handled differently, ie they shouldn't have laid it on with a trowel. Though it does provide the Supergirl team with an excuse for why Superman doesn't show up later this season to help Kara sort out Lex Luthor. I do have a couple of observations though. If Deegan's manipulations only affected natives of Earth-1, how come Sherloque Wells didn't see Barry & Oliver the way the Earth-38ers did? And would Laurel have coming from Earth-2 have seen them differently? Also why didn't they ask Cecile to mind-read them? Obviously the off-screen answer to my questions was they needed a reason for them to go to Earth-38 and enlist Supergirl's help. Also, if in Oliver's mind there's no Batman, who did he think put the Joker, Penguin & Riddler et al away given the state of the GCPD?
When there was talk of a member of DC's Legends of Tomorrow cameoing I couldn't help but wonder if they meant Brandon Routh would appear as Superman. By the way, I wonder if Gary was still a virgin in the altered timeline

? Speaking of Legends I loved the scene where they mentioned getting messages from Oliver, Barry & Kara and Ray replied: 'It must be that time of year'.
I have to say I'm really pumped for COIE next year (is it too soon to start an 'anticipation thread'?), but I felt that given the scale and potential impact of such a story, it overshadows the rest of the seasons for the Arrowverse shows, especially Arrow itself. I also can't help wonder if given the story's scale that they might treat it differently to past crossovers. The tease states its coming in 'Fall 2019' (Autumn for those of us outside North America), I wonder if they're going to do COIE as a lead-in to their shows, ie it kicks off the season, or perhaps it could be a separate mini-series. I even wonder if it'll last all season long across all shows, afterall it would be a great way for the CW to get people to tune in. Hopefully it'll include Black Lightning & the new Batwoman shos as well as the existing quartet and include characters as diverse as Jonah Hex and Superman.