I agree with a few people here that the show didn't really succeed with its tone shift this season.
In order to make the brainwashing believable, they spent too much time on Dory and Chip. I loved Cole Escola on At Home with Amy Sedaris (canceled a couple of weeks ago), and his performance, especially while impersonating Susan Sarandon, was fine, but it was basically torture porn, without enough things that could be redeeming.
The other three leads got some character development, that was mostly interrupted as soon as their focus was to find Dory. Yet, I loved Elliott joining Fox News and the details about it (the rivalry with his co-host, her fate, which got a great callback shortly before the Chantal episode, his lineup of colored guns, etc.) When the three of them end up together, they have some funny side plots (like the robbing), but the events do ultimately very little to push the plot forward, once again a sign that they are written as an afterthought to fill time while the focus is on Chip and Dory.
I'm mixed about the Chantal episode. The pre-titles sequence with the lawyer was a gem, but the confrontation with her family and her denial were somewhat forced.
Anyway, I loved the slapstick, especially the whole car chase near Babyfoot or the painful proposal by Drew's new girlfriend.
By the way, show is renewed for a fifth season, presumably about a newly enlightened Dory looking for redemption.