I love facebook and I think it improves my quality of life.
So much easier to keep in touch with people you can't see due location restrictions
For me there are a class of 'friend' that I would always not at at school, or take part in a group conversation with that I'd generally get along with, but never hang out that much on a one to one basis/organize a catchup. With facebook you still don't lose those people and when you bump into them it's nothing near awkward.
Personally I share music/articles/videos and generally can create a discussion out of them, which is very difficult in real life, and easier than doing so on a forum.
Also it's an amazing feeling when you meet a hot chick irl, and they go 'yeah I've seen you around on facebook'. Makes getting to know them heaps easier lmao.
I don't think it's really disadvantaged me academically or socially, I still head out to see people regularly, and never find myself actively using Facebook when I know I should be studying. That said there are some people that don't know how to manage their use of it.
I personally see video games as considerably more disruptive to one's social/academic life.