The DJ should spin whatever he is comfortable with, whatever format it may be. He is the one doing the work. I don't see the difference, as long as you rock the party. Yes, vinyl sounds better but believe me, 99% of the people there cannot tell the difference. 75% of the people who go out don't even know who is DJing, nor do they care. They are just out to have a good time and meet people. It is stupid, people have been having this argument for years. Who cares what the DJ uses? It's all about having fun.