“Stylish and sophisticated” is right! The movie is set in the 1970s (I think?) which makes for fun clothes and hairstyles, but also preserves certain attitudes (towards women in particular) and depicts a time when we weren’t nearly so reliant on technology (something that I imagine has made the spy game much easier these days).
The pacing is much slower than we’re used to in thriller movies now, I think, which makes for a very slow burn to the reveal (which we don’t actually see firsthand). There are also a lot of characters and motivations and alliances to keep track of, to say nothing of the jumping timeline, so definitely go when you’re alert because you will need to pay attention – but it’s worth the extra work.