I think despite some inconsistency, despite perhaps not being as hilarious as the show was at its best, despite the new formula (one episode for one character), the fourth season of Arrested Development managed to be intriguing and involving throughout. It's definitely not without its flaws, and a few episodes were never all that funny or interesting overall (Borderline Personalities, Indian Takers) but it got better as it went along, more focused, the story-telling seemed fluid. I've heard complaints that the pace of the show was slower, that it didn't move as fast as before, that there was too much narration, that it lingered in jokes for too long. I definitely saw all of this, but all of those elements, like anything, sometimes worked and sometimes didn't.
It's important to note that while this season is definitely a "different" Arrested Development in structure, it still "feels" like the classic show. The characters are definitely the same, despite what some might say. We just get more leveled, more even perspectives. For example, one might be inclined to say that Michael changed, that he's now like the rest of the family. But I think the new structure didn't change these people, it just made us more aware that yes, he IS a Bluth, and he always has been. Then let'stake someone like Maeby, who was perhaps always the least interesting and involving character in the first three seasons (although that's up for debate) and who became just one of the "Bluths", for better because now we see her on the same level as everyone else.
Overall, I don't think this was a "disappointing" season. If anything, the show is as ambitious as ever, in a different way, and what it sacrificed in some of its original pure-joke format it made up for in a long-running storyline and intricate web never-ending details and hidden agendas. It wasn't perfect, but there aren't many comedy seasons like this, and as far as I'm concerned it can stand apart the first three seasons yet still being on their level. What I am kinda fuzzy on is how the season ended, and how things like the Tobias/Mark explosion or Lucille 2 mystery weren't given definite ends. But of course, this means we get another season, or a movie! Right? Right!?