I still believe that the little quiet Northern Tools compressor with 3/4-gallon tank is a much better deal than the Habor Freight one with 3-gallons tank at the same price.
I tested one. The noise is no higher than a typical airbrush compressor from Iwata or Sparmax, but the pitch is slightly higher, just barely. It is not the supersilent type at $600, but you can talk comfortable without raising your voice while airbrushing.
The Northern Tools compressor cylinder head (the part with the vertical heatsink fins) gets as hot as those house brand sold at TCPGlobal. If you leave it running continuously for 30 minutes, it is about 45 degrees F above room temperature. It is quite acceptable since the compressor has auto-on-off and would never run continuously. In normal use, the head will barely get warm to the touch.
The auto switch turns on and off at 45 and 60 psi respectively. These are very good to allow good pressure margin for different paints in most airbrushing jobs, except not quite enough airflow and pressure for T-shirt airbrushing. The airflow was very steady with all of my airbrushes. As usual, with compressor at this price point, your milage may vary.
I did not realize so many of you got this compressor. Please, report back in 6 months and a year. If it still runs strong, you got a hell of a deal. Good luck with your new toy.
Disclaimer: I have no relationship nor know any individual at Northern Tools.