Some of you might already know this, but just in case...
I'm about to run my PStwo for 3-4 days straight with a dirty scratched up disc. It still has the seal intact so before I rip it open, I'm doing this test. If it survives then all should be good with the world. If it dies, then back I go to EB for a replacement.
I got a few games from the local video shop. They were pretty scratched up. Should do fine. I put a few extra finger prints on for good measure