Pros : I love this screen system. I get perfect round melts each time and don't have to do any cutting or edge polishing when they are done. The glass melts thru the screen more easily than other melt molds leaving LESS left over glass to deal with. Because of the size of the screen I can arrange glass colors on it to get many different patterns. The bottom ring can also be used by itself. Just line with fiber paper.
Cons : I have used 8 times since I purchased and have no negative feed back.
Other Thoughts : I spray with the Boron Nitride both the inside ring below AND THE SCREEN ABOVE.