I agree. Sure, on paper it sounds like it could be a complete rehash. I remember someone made this WAY back before any details about TDKR were known and it became something of a meme on here if I'm not mistaken:

Now, it
is kind of funny how strangely on target that is, but the thing is- the execution of these elements in TDKR made it feel completely fresh and exciting, to me anyway. A lot of that has to do with Bane and the type of evil that he represents.
What's so messed up about Bane and Talia's LOS is that it's like they themselves inflict a situation upon Gotham wherein it's allowed to become more and more morally depraved and in need of "cleansing". Then again, this may not be so dissimilar to Ra's after all since he himself originally attacked Gotham economically, which helped grow it into the cesspool of crime and corruption we saw in Batman Begins. But that's a very subtle similarity.
I also just really love that Ra's al Ghul casts such a shadow over the trilogy. He is given some of the most iconic and important lines in one of the first scenes of
Begins, and they echo very strongly into
Rises.
If we compare this trilogy to
The Godfather, Liam is the Vito to Bale's Michael. Only it would be a story where Michael ultimately rejects the mafia lifestyle and chooses a path of good. There's just a lot of richness there, especially when you get into Bane and Bruce being the two estranged sons of Ra's, individually embodying his best and worst qualities.