[jff]

They'll pipe up if the question is something like "What's the flag to make ls display in color?". IRCers are generally pretty quiet if you ask something actually technical or involving the code, or they'll just offer up a lot of speculation and irrelevant links. My theory is that the real project leaders and developers use mailing lists because they need to get work done, not watch IRC.

[elbear]

That depends a lot on the project. I've noticed significant difference in the attitude of several IRC communities.

[jff]

Definitely true. It can be really great if the main developers are actually using the IRC channel to coordinate development, but I think that can only really work when there aren't a ton of users to be poking in all the time. Kind of a Catch-22 problem; Linus would not be well-served to hang out on a Linux channel, because (as anyone who has seen his Google+ posts can testify) an army of sycophants would feel the need to interject their own non-content responses to everything he says. A small project, however, can still coordinate among developers while helping the odd user who shows up.