So I’d actually read the book a while back, but I just never got around to posting my review here 
On the whole I think it was a pretty solid Bond adventure. As a prequel, it necessarily had to be a bit stripped down compared to some of the later more bombastic and intricate Fleming plots, but Horowitz works perfectly with this constraints.
The ‘prequel’ stuff is obviously what drew me (and a lot of others presumably) to this book. There’s really not a lot of it, but what is there is simply perfect. I especially loved the early chapter with Bond’s second kill, the one in Stockholm. For years I’ve wondered how that played out and I almost squealed in delight finally seeing it being put to page (well, as much as one can squal in delight about a scene where a man is being brutally and cold-bloodedly stabbed to death in his own bed!)
I also loved the bit about the ‘origin’ of the vodka martini “shaken not stirred”.
The early chapters and that little easter egg apart, this is a pretty by-the-numbers Bond adventure, albeit with a lot of interesting aspects. Sixtine certainly. Yes, I did get a bit of a “this is a post MeToo Bond Girl” vibe from her character, but she was nonetheless written beautifully and fits perfectly into Bond’s world. I suppose if there’s any story where you can afford to have the Bond girl be more competent than Bond, it has to be an origin story. Plus, she truly was a fascinating character - the kind whom I can believe existed during the Cold War, but who would be totally at home in the 21st century too.
I also couldn’t but help notice a bit of contemporary commentary with regards to Irwin Wolfe’s (the American millionaire) plan. He was a staunch isolationist who’s plan revolves around making the United States withdraw from foreign interventions and concentrate on the home front - which kinda echoes Trump’s rhetoric in a sense. Though maybe I’m just reading too much into it 
I loved Bond’s little heroin trip. I guess I’m not the only one who felt it was a kind of meta-nod to Bond in the films and the popular perception of James Bond as an immortal invincible action hero!
One thing I found a tad incongruous was Bond’s spot decision to execute the CIA agent. It just doesn’t feel like something Fleming’s Bond would do, though I can easily see Craig’s Bond doing it, and maybe Brosnan’s Bond as well. We never really got to see the decision and its fallout explored much, and probably never will, so it seems like something just tacked on to the ending as shock value.
Otherwise, this was a great read on the whole. If the next novel is also to be part of the Fleming timeline, I’d love to see Horowitz return. Next time, I hope he does a novel set a little later in Bond’s career - between Thunderball and OHMSS, when he’s on the hunt for Blofeld would be a nice little gap to fill. Or maybe a book set JUST after The Man with the Golden Gun, that explores the long-term fallout of Bond’s brainwashing at the hands of the Soviets and all the traumas he’s been through over recent years.
