OK folks I have just given it a trial run. I totally deflated my rear tyre set the unit to 42psi and set it running, it took 9 minutes 10 seconds to fully inflate the tyre. It shut off when it reached the preset pressure. I checked the pressure with a calibrated PCL digital inflater and it was bang on 42psi the PCL measures tenths so I was pleasantly surprised with the accuracy. Although the air going in was warming up as we went on, so that would affect pressure and I will check it again later but it would certainly get you out of a fix. It didn't get overly hot in operation, the air tube was warm to the touch but not burning hot as some can be.
So it gets a big thumbs up from me.