Agree with all of that Mickyd.
To answer the question though...
The difference is that this group of forums has a purpose, in most cases the theme of the conversation is whatever the thread topic is. Sure we go off on a tangent every now and then, but essentially the forums here are used to communicate on a specific topic related to one theme.... bowling.
As for facebook.... i hate some of the stuff that i get told about, to the point i have said to peoples face, dont tell me about what he said she said on facebook i simple do not care.
You are right it is easy for people to use it correctly, but its the misuse of it that i have a problem with. Abusing, harrassing and b*tching on facebook is out of control, ive actually not heard a 'good news' story out of facebook, id be happy to hear one.
The worst case ive heard is the poor family who found out their Son and Brother had died in a car accident because one of the survivors posted RIP *insert name here* whilst being treated for minor injuries whilst still at the scene fully aware his mate was dead still in the car. A stupid one off decision by the facebook poster? Probably. But still imagine logging onto facebook and being made aware of a death in the family before the police can even identify you. Feel sorry for the family. *rant end*