I have picked this series back up as well, and I'm 12 episodes in now, usually just watching 1 or 2 a day. Thoughts:
* The main 3 girls are awesome. Mio is my favorite, but Yukko never fails to make me laugh and Mai's deadpan behavior is brilliant.
* Hakase and Nano are too cute for words.
* Gundere's flustered reactions to Sasahara are great.
* Yukko's mom is a BMF.
* I like Mio's older sister. We need more of her.
* The dialog between the coffee-shop girl and Sakurai-sensei made me melt a little bit.
* Space Parsee.
* Helvetica Standard is a weird name for a manga within an anime.
* The ED is so frickin' catchy.
Overall, this show is so random, and I like it a lot. I've not seen something this random since Pani Poni Dash, IMO.