I view the 60s and 70s as still noirs but late and distinctive. For me, neo-noir begins in 1980 as a growing body of work. It maybe has roots that the critics identify as 1967 Point Blank, but that kind of thing is a point observation and we're talking about the whole distribution.
I find that the noirs are more un-self-conscious. Each one is more a whole or integral piece of work that integrates all the different aspects that go into a motion picture.
The neo-noirs tend to be more fake or concocted, more outrageous, more manipulative. They contain some amazing technical improvements or extensions, to be sure. The neo-noirs go out of their way to leave viewers in the dark or confuse them, but this doesn't always work to making these movies better.
Neo-noirs attempt often to be slick, cool, modernistic. They're more conscious and this hurts the artistic side of things.
Start with the credits at the start of neo-noirs. They're often drawn out too long. Beneath them quite often are glimpses of stuff that you can hardly make out.
The music is better in the noirs. It fits the situations better and it's more emotional, part of the integration aspect. A work of art is better in my book when it has an integral quality. I can only take repetitiousness, rock-based sounds, rap and hip-hop up to a limited point.
The audio in noirs is better than that in many neo-noirs. I use a lot of subtitles for neo-noirs because of the whispered lines. I never need it in noirs.
Dialog in noirs is far superior to neo-noirs in general. The ability to invest the lines with meaning and the acting ability to deliver them are superior in noirs.
The stars in the old movies are more mature and wear much more easily on us. The new cats often seem like teeny-boppers or immature. They often look lousy and act lousy. Acting has become more stilted and drawn out.
Too much vulgarity in newer movies. Too much sex. There really is a lot of far out stuff, bloody and violent, being put up on the screen. The action movies have very far out stunts.
Cinematography in new movies is often superior. Amazing close-ups, vistas, flying shots, etc. Beautiful stuff, especially the out of doors. I like it a lot. But when I go back to the noirs, I see that their beauty is very great and it's in the service of the story and the whole movie. It's typically arranged and lit better. Set design is lovely and natural. In the neo-noirs, I get the feeling I'm looking at what someone arranged. In retros, the lipsticks are too red, the costumes too much, the old cars too bright.
If we pick the best of the neo-noirs, naturally they are going to hold up well. We're talking about the medians of the two distributions.
By the way, I disliked "Strange Days" a great deal. I do not like any of Bigelow's movies. "Chinatown" should make the top 25 list. If I made a list (who knows?), it would be quite different than Kevin Olson's. I might have two lists, for bigger productions and more modest movies. I like a good many of the modest movies more than the bigger ones.