Character growth is a very important part of any story, but unprecedented and unrealistic character developments over short periods of time can be very confusing and weird. While watching GSN i was half expecting Nozaki to suddenly become uncharacteristically romantic or Sakura to try force feelings on Nozaki or even for Mikoshiba to come out as a brooding character hiding behind his cheer, but nope. All wrong :D
I loved the fact that all characters were true to what they are and still managed to incorporate each other into their lives without intrinsically changing what they are (which is what happens in real life). The gags were hilarious. i laughed my butt off when Sakura was supposed to praise Mikoshiba and she went "-___- Sugoi sugoi", when Mikoshiba finds out dating sim games and he and Nozaki play together, yo get the point.
I genuinely enjoyed this anime. If you like something with a light mood but still pretty satirical and witty, this is an anime for you. Don't expect romance, just watch it for what it is. Pure awesomeness.
P.S. I love obnoxious and easily manipulated characters like Mikoshiba :DD