The metro is pure brutalist, through-and-through, and it's utterly amazing. But you're inhabiting the space; there's little-to-no contrast with foreign elements; and the nature of the structure means everything about brutalism, artistically and functionally, could be exercised to its best effect.

I will say that I've always disliked most of the above ground platforms, for the same reasons I dislike brutalist architecture generally. The underground platforms transport you to its carefully constructed world. The above ground platforms don't and probably never could have the same effect.

As time goes on the metro has been slowly adulterated, but it's still amazing.