This comic, the brand new introduction to a brand new Superman in a brand new timeline succeeds in establishing everything, right off the bat. Within this first issue, you get a clear idea of Superman's powers and limitations, his attitude, his alter-ego, Clark's job and status, Lois's personality, Jimmy Olsen's personality, and a very clear idea of who Lex Luthor is and what he does.
In short, if you've never read a Superman book before, you'll be completely up to speed by the end of this book.
But what makes that amazing, rather than just doing an extremely good job? It's all done through showing, not telling, and it's highly entertaining and full of action, too.
This is my third favorite book of the day, sure, but only because Batgirl and Swamp Thing were so incredibly good. This book would've been the best thing I've read in months...except that Batgirl and Swamp Thing came out the same day.
I never thought I'd be gushing over a Superman book...but I am.