Something about the most recent update to the Azahar emulator has made all the 3DS-generation games completely playable without (most of) the annoying freezes that used to plague them so I've finally begun playing through Y and Moon, haven't really done anything yet in either but I picked Fennekin and Rowlet as my respective starters.
Went with just Moon rather than Ultra because I've heard it has a better story even though USUM apparently adds a bunch of new content and objective improvements to the rest of the game. Might give USun a shot later to compare.