As usual, I'm looking at the Hugo finalists as owned on Goodreads and LibraryThing – LibraryThing is my first love, but Goodreads seems to have about 30 times as many users, so I am including stats for both. (I prepared this a couple of days ago so it may not be 100% up to date.) The tables below give the number of people who have reviewed each book on Goodreads, their average rating, the number of LibraryThing owners who own each book, and then the average rating. They are listed in order of the geometrical average of the first and third columns. (Which in most cases is the same as each column taken alone.)

Best Novel

This is actually the tenth year that I have done this calculation.
Last year's winner was fourth on this metric, and had the second highest rating on Goodreads and joint third highest on LibraryThing.
The 2019 winner was third on this metric, had the second highest rating on Goodreads (again) and the second lowest on LibraryThing.
The 2018 winner was second on this metric and had the top ratings on both systems.
The 2017 winner was also second on this metric, had the third highest rating on Goodreads and the second highest on LibraryThing.
The 2016 winner was fifth on this metric, but had the top ratings on both systems.
The 2015 winner was fourth (out of five) on all counts.
The 2014 winner was third (out of five) on this metric (counting all the Wheel of Time as one) and in the middle-ish on ratings (depending on how you count the Wheel of Time)
The 2013 winner was top on both metrics (uniquely!) and third (out of five) in ratings on both systems.
The 2012 winner was last on both Goodreads owners and ratings, and had the lowest rating on Goodreads, but was ranked and rated third (out of five) on LibraryThing.
It's clearly an imperfect indicator. The eventual winner was in the top half of the table in four of the last nine years, in the botto, half four times, and in the middle once.

Best Novella

This year's clean sweep for Tor.com is not unprecedented – Asimov's Science Fiction got all the slots in this category in n1991 and 1996 – but it is unusual. It means we can make the same comparison as follows:

Of the five finalists published as standalone novellas last year, the winner ranked top on this metric; the 2019 winner was second on this metric but had top ratings from readers; and I don't seem to have done it previously.

Best Graphic Story or Comic

A clear leader! But last year's winner was actually last on this metric, and had the second lowest ratings; the 2019 winner was third and had the second highest ratings.

Lodestar Award for best YA book

Last year's winner had the second lowest place on the metric, and among Goodreads reviewers; but LibraryThing readers ranked it top.The 2018 YA Award winner was top on the metric, and among Goodreads reviewers, but only rated fifth out of six by LibraryThing users.