Pros : I love these running pliers because they are so easy to use. Just line up the line on the plier that's located by the top screw with the score mark you previously made on the glass and gently press. You don't risk cutting your fingers when you use a tool like this versus snapping glass by hand.
Cons : None
Other Thoughts : Over time, the rubber cover will wear out--but I didn't need to replace mine for several years and I use it all the time. I bought extra pliers so I could teach classes