Watchability on Both Sides of the Pond
My main draw for seeing "Sherlock Gnomes" was James McAvoy. Dude is eminently watchable. And I'd made the mistake of skipping "Gnomeo and Juliet" during its theatrical run. But I knew nothing else. Then I got in and discovered that Johnny Depp was Sherlock. My whimsy's now doubly justified. In terms of watchability, he's right up there with McAvoy. Just less British. Although maybe he's trying to be that too.
Also, the soundtrack seemed to be built around Elton John. That's usually a good portent for animated movies. Just ask "The Lion King". Oh, wait. You can't. Because it's too untouchably successful and awesome to hear you. You should probably just see "Sherlock Gnomes" and find out for yourself.
Bonus Question!
Hobbits versus gnomes!
Baggins > gnomes > non-Baggins hobbits
Gnome boy.