The behind the scenes footage isn't necessarily that enlightening, but it's interesting to see that the new film is being shot on 35mm (though thanks to the Kodak deal, directors and DPs will have the option for the foreseeable future). While the first Sam Mendes Bond film Skyfall was captured on the ALEXA by Roger Deakins, the new film Spectre is being shot on 35mm by Hoyte Van Hoytema, who was mostly recently the DP on Christopher Nolan's completely celluloid Interstellar.
There are some enlightening thoughts from Hoytema in this interview, where he mentions that comparing film and digital is a little bit like comparing apples and pears:
This switch back to film is similar to what happened with the TheAmazing Spider-Man films. While both were helmed by Marc Webb, the first was shot on the RED EPIC by John Schwartzman and the second on 35mm by Daniel Mindel. A change of DP was also a change in shooting format. This isn't to say that any format is necessarily better than any other, but it's nice to know that big films like this (and the professionals who make them) will still be able to make the choice about what works best for them on a specific movie.
We've shared this set of videos where Deakins talks about shooting on the ALEXA and the tests they did for Skyfall, but I think it's worth sharing again: