Overall, this is a handy tool. The information booklet is a bit outdated, and the methods they suggest for separating the glass is a little tedious and doesn't leave as clean of a line as others I use. However both of those things have little to do with the product itself. As far as scoring the glass goes, this tool makes it incredibly simply. The first time I tried it, I got a perfect score. I would suggest alternating between hot and cold water after scoring to get a better cut though, instead of their tapping process.