The best way to describe it is to say it's like happy hour at the local bar. If you have urgent basic care questions you need immediate answers to, it is probably not the place to go. But, if you want to talk to fellow hobbyists about your day, or other stuff that interests you, those seem to be the most common topics. If you also have a question or two, people are usually happy to discuss corns a little bit.
Chat usually gets going around 7PM central, so that is the best time to find people there. If nobody's there, just wait about 3 minutes and someone else usually shows up.