There are lots of pros... easy placement because they are totally see through & less expensive. They stick to your clear blocks very well. They are bendable which is a pro and a con. If you are having trouble getting your image to stamp very well, try putting your Stampin' Pierce mat under your cardstock. Sometimes photopolymer stamps can get brittle, and crack and yellow over time, but Stampin' Up has improved the formula to lengthen the life of these stamps.
Flower Patch stamp set (134207)
Flower Fair Framelits (133731)