I like a lot of it's ideas but honestly I wish Miller had just planned out the story and then given it to someone else.
I honestly hate the way he writes characters/dialogue/narration. The Miller-isms ruin it for me. I find even Miller's good works before the dark times to be cringe-fests to read.
Also I think I'm starting to retroactively resent TDKR more because of how many hundreds of times I've heard "We want to make this interpretation of Batman like the Dark Knight Returns!". It's just frustrating to me that this is the only Batman story people ever talk about.