I liked season 4, but it was by far the worst season.

The only new character I really liked was Argyle Austero.

Some of the jokes seemed like they would never end and when they did, they didn't have much payoff. Like Gob's "Sh-sh-should" scene when he's at Ann's house; it wasn't as funny as the first time he did it.

Some scenes were very dull like when Buster was being tested with his giant hand. He squirts toothpaste on the nurse and she says something like "Yeah...you squirted me." in a quiet tone. And the scientist (Diedrich Bader) had similar reactions just calmly observing things without saying anything memorable.

The characters seemed off too. Lucille 2 was talking to Lucille as she stole the Queen Mary and seemed rather aggressive even though in seasons 1-3 she was mostly friendly to Lucille and didn't seem to totally realize that she was being passive aggressive towards her. Also when Buster dropped the "2" from her name it seemed odd when she asked about it; I don't remember anyone calling her that to her face.

In my opinion, Tony Wonder didn't really have any reason to have a rivalry with Gob. Gob got the better of him one time in a very minor conflict and all of the sudden Tony is out to destroy his pretty much nonexistent magic career.

I read recently that since Mitch Hurwitz was co-directing all of the new episodes, he wasn't in the writer's room as much and he would call them for updates. I wish I could remember where I saw that. That was probably a huge factor in the difference of humor between the fourth and the original three seasons.

Extending the length of the episodes probably didn't help either. Normal episodes of TV are usually either around 22 minutes or 43 minutes. Having the new episodes be around 30 minutes might have messed up the pacing a bit.

After saying all of that negative stuff I'll reiterate that I did like season 4 and add that Arrested Development is by far my favorite TV show.