Most of what I know about bitlbee comes from the home page.
I don’t have much occasion to use bitlbee, mostly because I don’t spend much time in chat channels. I respect them as a viable source of information, but I find them a bit saccharine at times.
That being said, an IM client that splices with an IRC tool is probably quite useful for a lot of people.
So I can assume it works like it should, even though I haven’t actually used it. I hear quite a few testimonials, particularly among people who are fans of irssi.
I suppose it works within other chat clients too. Chime in if you have an experience to report.