I don't like working on disc brakes - bleeding, truing rotors, aligning calipers - you name it, I don't really enjoy doing it. But I really hate getting a lot of resistance because the rotor isn't aligned with the caliper. This tool definitely helps. I've been using it with Formula brakes, where my complaint has always been that there is very little space to play with between the pads and the rotors. What I've found with this tool is that it is easiest to just determine which brake pad is closest to the rotor (in my case it is usually rubbing), then loosen the caliper bolts, insert only one of the feeler guages where there is no space between the pad and the rotor, squeeze the brake lever and slowly tighten the caliper bolts. Sure - you could probably just by a feeler guage, but this tool doesn't get lost in the tool box and it has the added benefit of being able to help spread the pistons apart. This tool, combined with the rotor truing tools from Park have made it much easier for me to keep my brakes running drag free.