There's actually a pretty good image that summarizes the differences, I'll see if I can find it later.
But really, the big difference was the lack of social media integration and that you were a different person on websites. If you saw someone with the same username, you would go "Oh hey are you star_fighter_xX85 on <insert forum here>?" Now it's a given. Never mind the fact that people now tie their online personae to their social media - I say as I post on social media.