OK here goes.
I think the way people have decided this movie needs to be better than TDK for it not to be a disappointment shouldn't be the way to go about it. Well I don't know if anyone else was doing that, but I know I was... then I saw this. I was worried because of all the criticism from people who saw it early on here about undeveloped character this and leaps of logic that. But if I hadn't read all of that, I wouldn't have noticed any of it in the movie (as just an average filmgoer).
First of all, people say they're disappointed that Bane is not as good as the Joker, but I don't even care. That was another part that does not need to be repeated, one piece of the bigger story. And Bane is plenty sinister and menacing by himself to serve as a good villain in my opinion. And again, he's just one character that helps tell the story of Gotham in these three movies.
Secondly, people complain about the action. I thought it was actually excellent but hey I'm no action/directing aficionado, I just know I enjoyed the hell out of watching it. I enjoyed all the action in the other two movies too, though I think the best action scene is probably in this one.
What's most important is that the film rounds off the story in a meaningful way, and fuck yes does it do that. I don't even know how I rank it compared to the other two. I just know that it doesn't stick out like a sore thumb in quality compared to the other two, and there will be valid reasons for people to call any of them their favourite down the line. Everyone will have a slightly different opinion, but I just think this is another worthy addition to the series and that's the crucial part.
As I sit here and type this now, I think it might be my favourite of the whole trilogy. It might also be my least favourite. But the point is the trilogy ended brilliantly and exactly as it should, with a hell of a lot of surprises along the way. If it is your least favourite, it won't matter too much. I think this needs to be viewed as part of (in my opinion) the best trilogy of my admittedly not very long lifetime, and much like Star Wars, it shouldn't bloody matter which one is the best, they're all crucial parts of the big puzzle.
Basically, if GAF has you worried and you're just an average Nolan Batman fan, then don't worry anymore.