I suppose it depends on how many different operations you are doing "at once" (or in quick succession) and how far the compressor is from the work area. If you have the compressor in a separate room with hard pipe to the work area, I would consider a master regulator at the tank, and then multiple regulators for different types of operations--painting, drilling, riveting, etc. It would depend for me on how often I would need to get up and go to the tank to change the regulator setting.
Also, if you have an application that requires air at very low pressures relative to other applications, often it is better to install a secondary low pressure regulator for the low pressure operation so that you get a bit better control over the pressure available. Taking a large pressure drop across a single regulator is often less precise than using multiple regulators.