Pros : The mold is easy to work with and provides a nice finished product with very little work.. A full fuse and a slump is all that is needed
Cons : The mold size is not a true 12x12, it is actually 11 3/4 x 11 3/4. You will need to cut a 1/4 inch off each side of a 12 x 12 piece of glass. It is sometimes difficult to cut off such a slender piece. It would be nice if you did not have to do this and the mold was a true 12 x 12.
If you do not do this, your mold is subject to cracking as the glass cools because it has wrapped over the edges of the mold. Knowing this beforehand can prevent this from happening.