It took me a while with feeling crook but I finished rereading Shades of Grey and now Red Side Story. Tbh... it was a bit of a let down and I don't think it's just from the heightened expectations after 14 years' wait...
no spoilers, not even descriptions of the plot or characters, just long rambling thoughts
IMO it wasnowhere near as good as the first book - felt like the author phoned it in to get the book out of the way already. Of course the second one was never gonna have the same effect as the first with its inimitably creative and detailed world building, but where the first book was so tightly plotted and revealed tantalising hints so masterfully and with great wit, the second felt distinctly more clunky and expository with its info dumps and reveals, like it was going through the motions.
It also felt repetitive at times in beating readers over the head about character motivations and old plot points - like we needed reminding because of the huge gap of time between releases? Or maybe the author needed reminding? He couldn't keep his own continuity right (he had someone specifically helping him with this but a minor character's plot-relevant age in book 1 is mysteriously dropped by 3 years in book 2 where they are more prominent, so were even they confused?). I blame the book having two editors...
One more whinge, and maybe this last one is just because fans have had 14 years to theorise, but nearly all the major worldbuilding reveals/explanations in the second book could be correctly guessed in the first, and the second book didn't go much deeper beyond those revelations. I know they have to go through it from the characters' point of view within the world but it felt a bit "meh, we need more". But this complaint is perhaps taking the books more seriously than they're meant to be taken.
That aside it was a long awaited gift to be officially reunited with these characters and their world, and there were still some good nail biting sequences and whimsical turns to be enjoyable enough, plus enough plot threads to write a third book (if the author doesn't die first).