Okaeri isn't a radical change from the previous seasons, just little things here and there. They seem to have moved to the 3-segment style instead of part a/b, which is kinda annoying cause now I have to skip sections twice instead of once. Chiaki looks even more different now, which is neat. They did a pretty good job of trying to animate someone growing up physically; she looks a little closer to Haruka now. I feel like Haruka has evolved over the course of the seasons also - she's now a part of some of the humor and has a personality instead of just cooking/cleaning/school.
Overall, it feels like they were trying to transition Minimi-ke from purely great comedy to something that's more slice-of-life. It might not be for everyone, but it's worth watching just for the gems like Kana and Hosaka.
