Yo creo que esta review lo resume todo bastante bien...

Video: How’s it look?
All four of these Bond films have gotten the 4K treatment and it goes without saying that they all look better. How much better is, of course, a bit subjective. Looking back at 2006’s Casino Royale, it was the only one of these films to have been shot on film. As such, it has a bit of a different look and feel to it with a bit more grain and texture in some scenes. Looking at the later offerings, notably Skyfall and Spectre, they’ve benefitted from being shot digitally and sport a more modern look with cleaner lines.

There’s a fine line with things being released in 4K. Odds are it’ll never be a night and day experience where the new transfer is so outstandingly good that you’ll take your DVD or Blu-ray and have no use for it. And if it ever does come to that point, we’re clearly (pardon the pun) not at it now. I won’t regale the readers with technical jargon or HEVC, etc. What I will say is that each of these Bond films looks as good as it has to date. There are some subtle things that stood out, like the wrinkles on the foreheads (Craig and Dench in particular), there’s a bit more texture in clothing and some finer details that maybe didn’t stand out too much in a Blu-ray viewing. Of course, the HDR gives us a bit more color and each film has its own look and feel. Black and white levels are both elevated, giving us more contrast and, in turn an overall better-looking picture. All of the moves have the same 2.39:1 aspect ratio.

In summary, do these films look better than their Blu-ray counterparts? Of course they do. Spectre and Skyfall do look better than Casino Royale and Quantum of Solace, but that’s more due to the technology rather than a “better” 4K scan.
https://www.blurayauthority.com/4k/t...hd-4k-blu-ray/