Looking at pictures:
The ARB is $33 on Amazon. Stainless braid line. Chuck looks crimped on- so not replaceable? 0-100 dial gauge
Powertank is $70, poly line, swivel 90 degree end and replaceable chuck. Liquid filled 0-60 dial gauge
My extremeaire magnum air compressor is supposed to use a flow through chuck so air always runs through it. That's so the air line won't over pressurize and rupture since I'm running sans tank and pressure switch. I have a flow through chuck that I could put on the powertank model.