On Twitter you can't really get into much of a discussion due to the limited amount of words, and if your following someone, all you see is partial sentences, which might make sense to you if you were in the conversation, but not if your trying to catch up with somebody's life experiences.
Facebook and Twitter is too much.... I had to stop using facebook, i have over 2000 friends, but really no one uses it anymore because it gets annoying after a while. AND It's already been reported that those sites do give your information to the police or anyone "deemed important" who really needs it. Even if all of your stuff is set private it really isnt and it woun't be too hard for anyone to find you when everone can see where you been, what you look like, where you at, and what you doing....
I have both but am new to Twitter. My gut feeling is that Facebook is more of a "public relations" tool for most people whereas Twitter you are more likely to see honest opinions, regardless of whether they are "pc" or popular, or not. My view.
.Facebook only for reunion purposes
^_^