I use the "3 Strikes you're out" rule when playing with lfg (unless its oryx, I give them 5 chances). I've became familiar with all the strategies, cheeses, shortcuts, and whatnot. I don't care how we do it as long as it's efficient. To sum it all up - If you are dying or messing up often, I will boot you. If I'm not the leader, I have no problem with taking the checkpoint and starting a new group.