I've been browsing and I see people talking about how long Grisaia and such is, how it was a real downer and it seemed to go on too long.
I've read through grisaia 3 times and when I think back on it, it doesn't seem long. The longest novel I remember reading was Hoshimemo, but that was my first novel so my memory is probably really biased (as its also my favorite novel). Majikoi seemed longer than grisaia, so does G-senjou.
I'm terrible at keeping record, they are probably all wrong. To me, the longer a common route is, the more time I have to connect with the characters making the character routes much better. Then again, I have infinite time on my hands and can read 5 days straight without having to worry about doing anything. Maybe its just that you guys are time restricted? :/