Actually, back to the Dexter cutters, I once attended a framing workshop by a guy who was the curator of a major private print collection. He used a Dexter, but he said contrary to the normal instructions, he cuts from the front surface which allows seeing exactly where the visible cut is going. The only time this could be a problem is in the case of textured foil surfaces or the like, for which a strip of heavy paper or cardstock for the cutter to slide on can protect the surface. His major trick was that in starting the cut, you position the guide surface of the cutter body slightly away from the straightedge such that plunging the tip of the angled blade in snugs the guide surface right against the edge. If you put the cutter body directly against the straightedge and then push the blade in, it flexes and swerves outward as the cut starts, creating the curve. (The trick is to cut about 100 mats to learn what that distance needs to be!)

Now that I own a Logan, I go with that.