I just finished the season last night. It appears that like almost everyone, I was put off by the early episodes of the season. The format was weird, the characters' motivations were sketchy, there was an overuse of cameos, and an over-reliance on references to past seasons. I actually began to feel that bringing the show back was a mistake that would blight the show's legacy.
But around episode 5 or 6 things started to click into place, sub-plots began to emerge within episodes which made it feel like like classic AD, and the connections between the episodes began to emerge and explained some of the oddities in earlier episodes. By the end of the season I was sold on the format and considered the season a worthy successor to my favourite comedy series. It's not quite as funny as the first three seasons (except maybe the Rita arc), but it was a necessary to try a new format to move the plot along 7 years, and I think it was a mostly successful experiment. That being said, if there is to be a season 5 (and I agree with most people in that I'd prefer a fifth season to a movie) I'd prefer for the show to return to its original format now that they've caught up with the present.
I also intend to rewatch the season in the coming weeks because I feel this is a season that really needs to be rewatched to fully appreciate its brilliance. In that sense, it fully lives up to the Arrested Development tradition.