I don't know, it's a bit hit and miss. Some people want either a quick run or a quick carry. But I've also had groups willing to stay until the end of the DF timer. (Oh, how much it sucks when you're <10%, stand a good chance of clearing, and then the time runs out...).

Generally, when it comes to the DF, people say throw out all your expectations. Seems solid advice. You'll get great, terribad, and just really weird.