Pros: price, ease of use, easy calibration. It seems pretty accurate. Cons: None yet, although I don't have a more expensive sensor to compare this to. It needs to be calibrated before each use, but I wouldn't call it a major inconvenience by any means. This device gives me just enough confidence when cutting one step paint or when cutting harder on new clear coats that I won't crack. Dye. It wasn't expensive so if it lasts a few years I'll be happy with it. Shown is a late 1990's Saab, one shot paint job. That was about the amount of paint I expected to remove - just under 0.2 mil. Ry That Detail Guy St. Louis, MO