I'm easy to amuse and I wasn't expecting much out of Yuko, so what I got, I was okay with. Sure, Nana has the crazier song, while Yuko's chuunibyou interview isn't quite as farfetched. Still a far cry from Ranko or whoever else, but yeah. I guess overall, she's middle-ground, which makes me rank her the same as Syoko, simply because Syoko went entirely the other direction and somehow ended up being TOO crazy for me.
Nao's is just so full of trolling. Feels like the creators had fun with that.
On the other hand, Karen was a bit too mellow, and didn't have the benefit of having Sae's amazing voice. It's kinda telling when her voiceless mom is more entertaining than the idol herself.