I have to agree with JohnGG above - ultimately there simply wasn't enough Batman in what was supposed to be a Batman film. I'd go further though and disagree that it was a film about Bruce Wayne - it seemed to be much more a film about Bane, which is really not that interesting. It got too caught up in itself, and when Batman was on screen, he wasn't really cool enough. (Not Bale's fault - he was, as usual in the role, excellent.)
In the first film we had the Batmobile and in the second the Batpod and the shocking destruction of the Batmobile.The big cool thing in this one was supposed to be The Bat, but it was just awful. Ignoring plotholes about how it went unnoticed on a rooftop for the best part of six months, the actual gizmo was just laughably bad. Batman wouldn't be seen dead in it (yes, intended, for those who have seen the film).
And there really wasn't much else in terms of development, which seems like a waste of 6 years time supposedly elapsed between the events of the previous film and this one.
Lastly, why put silver plastic onto the Batpod? It made it look like a toy.
Ultimately, not terrible, but the weakest of the three and had this been the sccond film, I doubt there would have been a third and Chris Nolan's stock would not be where it is. The critics' responses seem to be very much like those to The Lord of the Rings - by the time the 3rd film comes out, they realise they have missed the Zeitgeist when they were less than enthusiastic on previous films, so want to look hip and say how great it is, when by pretty much any standard it falls short of parts 1 and 2.