It has its flaws, mostly that it has some plot-holes that leave it feeling a bit thin, and that it feels like it should have been two movies that were instead squeezed together (part one being essentially a loose adaptation of Knightfall, and part two being a loose adaptation of No Man's Land).
But its not really bad, in my opinion, and I actually rather liked the ending, which shows the narrative advantages of having a short, stand-alone series.
In the comics, the status quo in Gotham can never fundamentally, permanently change.
But because Nolan's films were a self-contained story that ended with DKR, it allowed Batman to do something his comics counterpart can never actually do:
Win.
And they say that the Nolan films are dark.
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All that said, I'd have been interested to see how they might have continued things from there, if they'd decided to use the Nolan Trilogy as the basis for a DCCU, rather than starting over (as I believe was discussed at one point).
I've even thought about writing a DC/Justice League fanfic set in the Nolan-verse.