I saw also the ARB "single" (my definition
), wondering what are the main disadvantages of this one compared to the "twin".
The ARB On-Board High Performance 12 Volt Air Compressor is permanently mounted to your vehicle, including a full wiring loom with air locker solenoid plug in contacts, mounting hardware with reinforcing bracket and a quality compressor isolating switch.
www.trailnomad.be
I have no compressor experience. But I bought recently a cheap Chinese compressor of 24 €. I tested it, it works, but is indeed very slow!