It's a totally different perspective and experience when inside the metro. I really dislike brutalist architecture, but in the DC metro station you're not just looking at it, you're inhabiting it. And the architecture isn't blocky, the waffle patterns notwithstanding. The ceiling is curved and completely uniform, without any disruption except for the passenger portals to outside. The elevated walkways also have curvature. There generally aren't any horizontal or sharply squared surfaces except for the escalators and benches, a contrast that was presumably very deliberate.

The metro is fairly dark (or was designed to be fairly dark). It feels cave-like. It's brutalist through-and-through, but for that reason it also makes you feel like you're simultaneously in an expansive and ethereal, yet protected and confining space. There's no clash with adjacent architecture (except where modern renovations fsck things up). You're transported, literally and figuratively.

Unfortunately the effect has been adulterated over time. Lightning has changed--variously too dark, too light, or just wrong shading. Arrival time signs (added early 2000s) disrupt the airiness, especially when near escalators or walkways, which were carefully designed spaces that dealt with narrow constraints, but didn't/couldn't have a margin for introduced elements. (Maybe they should've been integrated into the ventilation towers?) Poor maintenance of the ceiling means grime and water damage breaks up the uniformity. It's not quite the same experience as when I first experienced it in the late 1990s.