I personally wouldn't be able to use it b/c I have a HORRIBLE dial-up connection. For those of you that understand, I generally connect around 15 - 19 kbps. Talk about brutal. For those that don't understand, let me put it this way: Every time someone posts more than 2 pics in a thread, it's like watching paint dry waiting for the page to load. Generally, if it's a thread full of pics, I don't even take the time to read it unless I'm looking at it from work (T1 line).
That being said, I don't think it would cause a problem with things not being posted, or at least not on a large enough scale to worry about. It's basically the shoutbox without typing (can't usually load the shoutbox from home, either by the way). However, even with the shoutbox here, I don't think it really hurts the threads much if at all.
I know that if I have a question about something, I would post a thread for at least 2 main reasons: first is that I don't usually have time to sit on a computer for very long while someone explains something, so it's easier to start a thread and check it later for responses. The second reason being that I think that by having the thread on the forum, it could potentially help someone else, or perhaps dozens of others to read the thread.
Just my opinions, but of course everyone is entitled to their own!