I like the gym system, maybe because of nostalgia. I'd like to see something different too, but I'm not at all against the old gym system. The gym system could be changed some though. There are some theories in the anime that each region has more than 8 gyms, so it could be required to have 8 gym badges for the Elite 4, but with more than 8 possible gyms this could add more depth to the story, creating alternate story-lines depending on choices the player makes. That's a change I'd like to see, but it'd require a lot more work. However, if the story calls for it I don't think gyms are needed. Sun & Moon has Island Challenges instead, so the puzzles might encompass the entire Island I think there'll be less than 8 of them. The main purpose of gyms is to be a progress checker in the game for Pokemon teams, I'd like to see a creative alternative for this, but I care way more about a good story than if Gyms are in the game or not. I also think a tournament style system would work better for the Elite Four than for Gyms. Maybe like a progressive tournament after 2 badges or so, with the last battle of the first tournament being Lorelei, then 2 badges later Bruno, then 2 badges later Agatha (Just using Gen 1 Elite Four as an example). Just throwing out ideas here, sorry for the rant.