The episode plays better the first time you see it and it is one of the more fun episodes of season 13. I find the heist material-while fun-doesn't really gel with the show's overall vibe. Charly's intro episode is really the only time they were able to stick the landing on a heist story. This one is more rote and yeah I didn't need the injokes about Game of Thrones.
But my biggest issue with the episode is how it wastes Barthamus (the demon). No demon will ever fill Crowley's shows but Barthamus was a fun character; he was just a slightly more brutish version of Crowley and I think there was a chance for the character to have developed into a foil for the Winchesters. But instead the writers stick a "happy" ending onto this episode and Barthamus gets his just desserts. What could have been is rendered moot.