Pros : This bit worked great with my flexshaft drill and fits the with my dremel as well. It makes a nice, smooth hole, even as the bit begins to dull. I was able to make over 30 1/8" holes in 3 mm glass per bit using water as a lubricant. I've tried other bits that haven't been able to handle the load of these bits. This is the only one I'll spend money on. Well worth every cent.
Cons : Would like to be able to get a quantity discount on these bit.