Pros : can make an interesting paperweight with scrap
Cons : Make sure you have it filled sufficiently or the finished product will be unbalanced and not stand.
Even following the suggested firing schedules you will get a lot of bubbles.
Other Thoughts : If using a design, as pictured, it is difficult to weigh you glass. Make sure you weight the mold first, then again after filling and add more clear to the top if needed.