The last time I read a non-china mieville book that won as many awards as Jo Walton’s Among Others was Paolo Bacigalupi’s Wind-up Girl which ended its course winning more awards than Among Others’ current tally. That’s probably as much as you can speak about the two in the same breath – as Among Others was (imho) as much a pleasure to read as Wind-up Girl was underwhelming.
And not just because Am
Magic is what you make of it; the closest the ‘magic’ in this book comes to is perhaps the ‘magic’ in Bridge to Terabithia. So in that sense, it is only ‘science fiction’ if you want it to be, and ‘fantasy’ if you say so.