VIAIR 400P-Automatic RV compressor for $231 on Amazon, with free shipping
$20 less than the same compressor with the 400P-A package. I was shopping for a 400P-A (Automatic) and found the RV version for less. The only difference between the two is the RV package has an additional hose and tire chucks.
If you compare VIAIR's top portables, the 440P and 450P-A may cost more, but they don't offer a clear cut advantage over the 400P-A. The 440P lacks auto shutoff (but has +0.46 cfm over 400 series), and the 450P-A has -0.88 cfm less output than a 400 series (but gains a 100% duty cycle rating). Looking at the specifications, I wonder if the 450 is just a detuned 400 that runs a little slower & cooler, leading to an increased duty cycle. I'm surprised there isn't a 440P-A.