I started watching Bond films in the 1980s, so I'm quite happy to suspend my disbelief when it comes to rocket cars or space lasers. However, speaking as a regular commuter, there was one bit in the new film where I had to stop and say "No, that's not right." Minor spoilers follow.
During the film, Bond chases the bad guy into a tube station. Bond then takes a shortcut, by sliding down the metal bit between the escalators. Here's a photo of the escalators at a tube station:
I took that photo at Canary Wharf (on my way to the Jubilee line) but the layout is pretty common across London stations. Note the blue signs at regular intervals which say "Please stand on the right". As well as optimising traffic, I think that they are also in place specifically to stop people from sliding down. At the bottom, there are also the red emergency buttons to stop the escalator and the oblong metal bits. Bond slid down a "single width" escalator, so he wouldn't have been able to dodgy around them. I've also seen stations where they put railings up to separate the escalator queues into "lanes"; the railing then joins the middle of the escalator barrier, so anyone who slid down and avoided all the other obstacles would then land on their groin at the bottom.
Actually, as I recall this was a minor plot point in Octopussy: James Bond (played by Roger Moore) was sliding down a banister rail, then he saw a big wooden sculpture at the bottom which would be painful to collide with so he had to shoot it into smithereens with his machine gun before he got there. Now that's the kind of realism that I'm looking for from Daniel Craig.
sulkyblue has also written about problems with this film; her blog post is a bit more in-depth than mine. 