Watched all of Season 4. I think they deserve massive props for taking advantage of the Netflix medium... It starts out a little dull, but the season just keeps building and building on itself. Calling back and recontextualizing things you saw in previous episodes from multiple perspectives. It's like a style mash up of Arrested development, pulp fiction and memento. Jokes within jokes on top of jokes. It totally plays to the binge-watching pause and rewind format... which makes it pretty unique.
It is, unfortunately, somewhat tedious and a little exhausting. Like 9 hours of "There was an old lady who swallowed a fly". And I really can't say it's terribly funny. It has moments. It's brilliantly executed. It's very cleverly done... it's just not all that funny. I spend a lot of time watching the show and thinking things to myself like, "Was that Tobias? I think that was Tobias... I bet that will be funny later!" and 4 episodes later saying "Oh!.. I knew it... i thought that was Tobias!"... and not enough time spent actually laughing. It's certainly entertaining though. Just not all that funny.
In a way, this season reminds me of the movie "Primer" ... Some people love that film dearly and analyze it from every angle imaginable. The fans look down on the dullards who don't attempt to understand the interwoven storylines. The film is incredibly complex. It's almost complex to a fault, though... "Primer" is a brilliant film... it deserves credit for what it accomplished... but I can't really say it's a fun film. It's rather exhausting.
TL;DR: Season 4 is complex. It deserves props for the complexity and original approach. It's just not all that funny in execution.
Edit: The other issue with it is that the show was always an ensemble piece. Michael Bluth is the classic "straight man" while all the crazy characters buzz around him. Unfortunately, focusing each episode on a single character (which we know was necessary due to the scheduling conflicts of the actors) causes some of that dynamic to break. As a whole, the season is definitely entertaining, though.
