A few things I wanted to add:
* one of the "retro" aspects of the film was some very clear product placement, of the kind that I do not recall from the previous Craig outings, but which used to feature prominently in Bond films (particularly in the Roger Moore era, I seem to recall.) The (very unsubtle) Omega watch, for one thing; but I also see (mainly from posters around town, as well a cinema ad before the film) the Sony Experia Z5 smartphone, and a brand of vodka that I can't even recall now.
The Sony and vodka product placement seem particularly pointless to me, given that while the phone might have been on screen several times, I don't think you could ever tell that it was an Experia at all. Let's face it, lots of smart phones look pretty similar, and maybe it is just be my lack of observation skills, but it seems odd that you have to have seen the pre-movie (or TV?) ad to recognise the product on screen.
I think the vodka came out even worse. Or maybe it wasn't even in the movie at all: but the ad before the film indicated it would be. All rather odd.
* I have to admit, the movie did come very close to crossing my "that is such plainly ridiculous science, I cannot forgive it" line that (for example) Goldeneye hurtled over. (I won't repeat the problem in that movie - I mention it about every 12 months here - but it was unforgiveably stupid.) The Spectre issue - Q's laptop which (I think) was meant to incorporate an instantaneous DNA analysing scanner. Now, the movie survives this sequence because it was dealt with so quickly - I'm not 100% sure that this is what it was doing - but even allowing for the impossibility of testing for DNA via some scan, my readers would recall that I posted recently about the incredible unreliability of "touch" DNA analysis, and this was a ring being scanned, about the touchiest thing of all! In other words, even if the laptop could do it, it would be hopelessly unreliable. It is a pity that this survived in the screenplay.
* At a more general level, seriously, why can't studios pay someone sensible (pick me!) to tell them when their plot-crucial sciency-technology bit of ridiculousness is just too ridiculous to stay? You don't need a scientist to do that job: just someone who reads enough science magazines and has a good nose for what is just stupid given current technology, allowing for some extrapolation of what might be possible.