I think I'm the only one who isn't thrilled with Type Null decks. I've used them in both comp, casual, and PVE, and I always feel like it's behind the opponent even when I'm winning. I haven't had as much time for the game recently so I haven't been grinding comp as much but there seem to be several strong decks in the meta rotation at the moment. The ones that I've enjoyed most have been based around Buzzwole, Charizard, Guzzlord, and even Lycanroc.
I've also had crappy luck with some of the lower rarity cards that are staples in the new meta decks, so that's kept me from trying as many as I'd like too. Still, I'm enjoying the Ultra Beast meta so far.