I was really disappointed personally because it's Kevin Conroy - the Batman to a certain generation - finally appearing. Having him pass the torch and then die when his Earth was annihilated would've been much more appreciated and would've been nice if our Kate never meets her Bruce for some reason.
I wasn't disappointed, because most actors love the chance to play villains, and this was a great chance for Conroy -- who's played more different iterations of Batman than anyone ever -- to get to do something new with the role. And look at it from the other side -- if the story demanded an evil Batman, who else could've been better in the role?
I'm not really sure why everybody's so gaga over Cryor's Lex either, do I need to have seen Supergirl to really get the appeal? He seems... rather like a thug trying to make himself something more (and not succeeding like the Kingpin)?
That's a fair question. Lex hasn't really had room here to show much of his personality. It's been more about his actions than his motivations. He did have meatier material on Supergirl.
Oliver as the Spectre is excellent though, I've been speculating that might be his fate. It's possible that depending on how much he appears, Oliver might do the Hal Jordan take of turning the Spectre from the Spirit of Vengeance into the Spirit of Redemption.
Ooh, I like that. It would be fitting for Green Arrow to take Green Lantern's place in that story arc. And "Spirit of Redemption" sounds perfect for Oliver, whose whole series has been about redemption.