Pros : This has the potential for allowing you to make sure, repetitive cuts. It's probably a good idea if you're cutting larger - ie 2" - pieces, but for use in cutting glass for fused glass jewelry - ie 1/2" - pieces, the jury is still out.
Cons : The instruction book is abysmal. I defy you to follow this book and set up the beetle bit set. However, a little patience and some common sense and, I think, you can make it work. I am particularly frustrated by the cutting piece. There are NO instructions for this and the set-up of the item, as delivered, is not intuitive. There's a screw that could be an adjustment screw for accommodating glass of different thicknesses, but who knows. No instructions on whether the cutter needs to be oiled and, if so, how often. No information on when, if ever, the cutter needs to be replaced. No information on where you'd get replacement cutting bits. By the way the cutter bit keeps falling out of the holder and there doesn't seem to be any way of locking it into the holder. There's a little wire thingie on the side of the cutter apparatus which must have some purpose, but, again, who knows.
Other Thoughts : This "system" reminds me of the mat cutters used in picture framing. You position the glass to be cut against a stop and slide a blade which scores the glass. You then use running pliers to break the glass. Great idea! However, I bought it cutting small - 1/2" - squares and, because I haven't yet been able to get it set up (see "Cons:" I'm not sure it's going to be useful. Not quite ready to try to return it, but I'm close.