The ARB compressors use about 20 amps and produce about 45 liters/min.

The bigger the reciever, the longer it takes to charge and the longer it takes to fill your tires once you have used what is in the reciever ie. reciever + tire volume up to your tyre pressure. 2 gallons is good for one or maybe two tire pressure top-ups, after that you are "running on empty" then only charging it up to your tire pressure anyway between tires. Given that we usually have to inflate 4 tires, seems pointless (you can always blow a bead with another tire if you have a valve-valve link hose). Best bet is for one decent compressor for you tires (mine is 72 litres/min = 2.5 cubic ft/min), with the ARB as a backup permanantly connected to lockers. The ARB compressors are only 33-50% duty cycled. Don't bother with a reciever unless you HAVE to use air tools out on the trail.