Just picked up a Sonic Prospector last night- I was very surprised that the playfield cleaned up as well as it did- what's the difference in this playfield material as opposed to the other williams and gottlieb playfields? Most ball swirl marks cleaned up with my inital wipe down of the playfield- it was pretty dirty and had been in this gentlemans house with a sheet of plexiglass that was broken-in lieu of glass- I just got all the dust and dirt off of it and was pretty impressed that it cleaned up as nice as it did.