You'd end up with a shiny edge, and it's a lot more work than you think. You'd need some diamond pads to polish things and either an angle grinder with a water attachment and shaping wheels, or one for your wetsaw. If you want the edge to be a full 1/4-round, since the back of the tile is often a waffle shape in the middle of the field, the edge would only be straight if you did this on the outer edge cuts, and you'd throw away the middle strips (i.e., half the tile). Have I talked you out of it yet? Once you get it shaped, then you have to polish it, and that would require a series of diamond pads up to maybe as high as 3500-grit, depending on how smooth you want it. The alternatives are: buy their bullnose tile pieces; use something else on the edge (Schluter and a few other companies make edge profiles that may work, depending on your style preferences http://www.schluter.com/139.aspx).