Of the winners, I've seen
Gravity and read
Ancillary Justice. I've purchased Stross'
Neptune's Brood, but haven't gotten to it yet.
Gravity was interesting enough and I liked it okay, but it was not all that great to me. I didn't like
Ancillary Justice.
Of the nominees, I've read Brad Torgersen's "The Chaplain's Legacy" and "The Exchange Officers" and, for something completely different, Rachel Swirsky's "If You Were a Dinosaur, My Love". I can't speak to the winners but it must be a damn good story to be better than "The Chaplain's Legacy" (a tale of an atheist assistant to a dead preacher helping humans and trying to achieve peace when confronting xenocidal aliens). On the other hand, while I enjoyed the heck out of "The Exchange Officers" (the Chinese try to steal a US satellite and telepresence warriors defend it), I don't feel it was intrinsically Hugo-worthy (in an ideal sense - Hugos aren't worth anything any more). It was nominee-worthy, but not winner-worthy. With "If You Were a Dinosaur, My Love" (which you can
read free online along with several others) I can easily see hating it if it hits you wrong and I agree with the arguments that it isn't SF or F but it's an excellent story to me. I can't really describe the very short piece without spoiling it.
For nominees below the cutoff, I've seen
Europa Report for BDP-L and the
Sleepy Hollow pilot for BDP-S. I didn't like the pilot but gave it another try and then quit at the "witchburning is good" episode. Having seen both
Gravity and
Europa Report I
can speak to the winner this time and it's a disgrace to the SF community that
Europa Report was cut off when it should have not only made the final ballot but beaten the winner. Yeah, the "found footage" and "artfully glitchily edited" aspects of the production are too cute but the tale of a privately funded expedition to explore Europa, especially in terms of extra-terrestrial life, was one of the few truly "proverbially good SF movies" ever.
It's not a Hugo but presented at the same time and place and, of the JWC nominees, I've read Madeleine Ashby and Ann Leckie. I wasn't overwhelmed with either debut but I enjoyed Ashby's much more - she's more likable and seems much fresher and energetic than the 60s-feeling Leckie. (The actual winner was Samatar (who?) because Leckie withdrew herself on a technicality, IIRC. Otherwise, Leckie's actual fiction winning 67 awards and Samatar's winning possibly none and her beating Leckie is inexplicable. Leaving aside that the awards shower for Leckie is inexplicable in the first place.)