The Dark Knight Rises - letdown or not?
This is a matter of opinion, not a fact.
Opinions are subjective and vary from person to person. What one feels about TDKR depends on what he/ she was expecting from the movie.
Some of us went to watch the movie with an open mind, some were prepared to view this movie as the end to Nolan's Batman saga, this movie being the conclusion to Nolan's Bat universe.
Then, there were some who went in expecting to see a comic book accurate depiction of Batman and expected this a one of the continuing adventure of Batman much like Bond movies keep continuing the Bond franchise, with each movie being a new mission.
As Nolan had already made clear before beginning shooting of TDKR, he was going to end the trilogy, and we already got many "on Location" photos of Bane, the fight scenes between the Cops and Bane's Army, spy pics. of Talia, Catwoman and many other spy footage, which did kind of spoiled those moments on screen, this never happened with BB or TDK, so for some it may have been the case of knowing too much before watching the movie.
To me this movie was better than TDK.