Me and my friend have been very lucky with the DF groups so far. Really just the usual "Everyone says hi and stays silent for the rest of the run" but things went well, and it sure beats getting one where people try and force you to skip cutscenes or ragequit after a wipe (Bonus points there if they know people are new while they are not, and don't bother explaining anything either. Can't expect things to go flawlessly if people are new and don't know what's going on)