Actually, as far as I know, most small airbrush-type compressors are of the diaphragm, oiless variety. I know that is true of the Paasche compressors, such as the D500 compressor I have...so I would say it is a good thing. Diaphragm compressors, however, do tend to be pulsatile in their delivery of air, which could effect fine work--an air tank alleviates that problem.