Just read Batman/Superman 1 over my lunch break.
Good writing, superb visuals but I have no idea how and when this could logically happen in the time line. I ignores Action Comics: Men of Steel as well as the Zero Issues of Bats and Supes, it ignores much of the set-up of JL:Origin and does not mesh too well with E2:The Gathering as of now.
I know, i know it is early to judge a story after 20 pages, espcially one so well written and drawn, but it's strage that Pak always told us it will make sense when taking previewous books into acount, but it does not.