Except for the part where the writers would have to make plots up 3/4ths of the time since there's no way the games can come out fast enough for shorter sagas. And I'd argue about the character development being more noticable, since I don't remember much of that happening in the OI. Or Pokemon development, for that matter(Charizard Chills aside). There is the benefit of having important episodes closer together, but that's not a necessity if the writers can make fillers entertaining(as they've done, for the most part, in Shinou).Pokemon works better with shorter sagas overall. The important episodes are closer together and the character development and Pokemon progression is much more noticeable.
To contribute to the season at hand:
One major good point of the OI, in my opinion, was the variety in the gym battles. The various challenges Ash had to go through in the four gyms are probably the closest we'll ever get to seeing the in-game gym puzzles emulated in the anime(for those who care about that), but more importantly:They were fun! Sure, they were simple(Luana's double battle "gimmick" was so obvious that it became an official battling setup in Gen 3), but they added an element of creativity that was sorely lacking in the Kanto gyms. The GLs themselves were fairly memorable(except for Danny, who I had to look up since I couldn't remember one of the four OI GLs), although I guess the writers had to pay more attention to their personalities since they were making the GLs from scratch for a change.