I'mma be the odd man out. I'd rather they not keep hidden grottoes in the new game. They're a gimmick for B2W2. I kinda want them to keep dream world or add a new dream world like add on for the games. Maybe some pokewalker like item with dream world pokemon or some kinda ar scan card link upfeature with special pokemon cards that can be scaned more than once.
Leave the other in game gimmicks to the game that they belong to.