It seems a ridiculous thing to say. The Dark Knight Rises is already more than two and a half hours long. Everything that is in the movie is fantastic. There just needed to be more of some of it.
Batman's status as a symbol, for instance. Early on we see one child (from the trailers) who draws bat symbols and wishes for the return of the Dark Knight. All three movies in the trilogy have had one kid o represent the effect batman is having on Gotham's children, and in this finale it would have been appropriate, and better, to see more of this. It would have hilighted Gordon's mistake at the end of TDK even more. Harvey Dent could never inspire the younger generation the way Batman did (though there is an argument to be made that any inspiration a real life Batman would have on children could easily be negative).
Similarly, when things go to heck, one person makes chalk bat signals on walls as a show of defiance and hope that Batman would return to set things right. This is the aspect that should have been played up. Many more people should have turned to the bat as the symbol of resistence, and the faux batmen from TDK should have returned at that point. Of course without the real Batman they'd be hopelessly outnumbered and outmatched, but it would give the idea that Batman is first and foremost a symbol that the movie tries to convey much more resonance.
Finally, there is a reveal that, while good and effectively built up to, required just a little more follow-up to be fully justified. Even a three second action scene where one character beats some random person up would have sufficed.
Other than wanting more of those things to make TDKR more complete it is near perfect. The writing, characterization, and acting is great. The action scenes are what you'd come to expect from Nolan, meaning images of destruction that are works of art in their own right. The fights are finally shot from far enough back that they don't seem choppy and it is easy to tell what is going on. No, it isn't as good as TDK, due to missing those things I mentioned and the drop from Joker to Bane (who is still one of the best movie villains ever, just not as great as Heath Ledger). TDKR makes up for this, though, with greater scale and scope than ever before.
A great end to one of the greatest movie trilogies ever.