In reply to GrahamD:
Just watched it, having avoided doing so until now partly because it sounded like it was going to be Americanised, pseudo-intellectual twaddle.
I was way more impressed than I expected. And, apparently in contrast to your opinion, I felt like I barely registered the quality of any climbing sequences, as I was caught up in the inner mental turmoil (which I assume to have been the director's intention). It can't be easy to draw viewers into empathy for a mental state far removed from their own, but I think in case case they managed to achieve that, certainly for me.
I'd certainly urge anyone else who may have avoided watching it for similar preconceived reasons as mine, to give it a chance.