I think the the reason why that knife stab left Batman enervated was not just the physical injury itself, but because of the emotional impact behind it. Remember that Miranda Tate (aka Talia al Ghul) seduced Bruce Wayne in every way; emotionally, physically, and financially. Even in the comic books, Talia and Bruce shared a deep love for each other, in spite of their opposing ideals.

Honestly, I felt a bit disappointed with Miranda/Talia's fate. I wish they'd have left her death open-ended, and possibly even pregnant (with Damian Wayne, as in the comics). To have any form al Ghul alive to threaten Batman again in the future would've been great.

I LOVED the movie's reference to the Lazarus Pit with the hellish prison that birthed Bane and Talia. How Ra's al Ghul's "legacy" rose from the Pit to continue his work without resorting to the "back from the dead gimmick" was a nice touch.

P.S. I thought Hathaway's Selina Kyle (and Catwoman) was respectable. I enjoyed her character thoroughly. I loved how unapologetic she was about betraying Batman to Bane. A part of me expected her to have a pet kitty, was kinda sad she didn't.