I’ve read both Nettle and Bone and Nona the Ninth, and while Nettle and Bone was a fun read at no point while reading it did I think “hey, this is Hugo Award material!” It’s firmly in Kingfisher’s romantic fantasy wheelhouse, and hits all the tropes that subgenre is known for. I’d say the romance is more subtly threaded through the main plot than in her Saints of Steel series, but I came away from it with the sense that it was just a very good piece of genre fiction.
In contrast, Tamsyn Muir’s Locked Tomb series (of which Nona is the third entry) has been such a delightful, genre-bending romp that I would put it well ahead of most anything else I’ve read in the last few years. It remains to be seen if Muir can land the plane with Alecto, but (while I admit it’s a challenging read at first) Harrow the Ninth in particular is just so masterful at spinning an arch-gothic space opera tale through the eyes of a very unconventional and insanely unreliable narrator, and it’s peppered with mad twists to boot. I’ll grant that it was up against stiff competition from Arkady Martine’s Teixcalaan novels in the last couple years, but I personally would still have given Nona the Ninth the nod over Nettle and Bone this year.