While we'd probably come to a consensus regarding David Chase being a dink in general, I strongly disagree about your opinion regarding season 3. Most of its episodes aren't written by Chase, some of them put the light on both Terence Winter (Boardwalk Empire, Vinyl) / Tim Van Patten (Deadwood, Rome) work. Also there's the episode written by Michael Imperioli and the utterly praised Pine Barrens episode, written by Steve Buscemi, which is one of the most acclaimed TV show episode ever.
Season 3 wise, Chase wrote the season premiere with the FBI / Adriana tennis lessons stuff, the episode with Tony's mother death and the season finale (Jackie Jr getting clipped, AJ and the militay school stuff, Adriana and the Feds, etc). Those are milestone episodes, they're in my opinion top notch material, a lot of stuff happens, sometimes in a definitive way, Chase being known as attached at his characters to the bone and being a story conservative, I think there's no room saying he "dinked" the season.