I was looking at compressors last year at ARB, Smittybilt, and Viair.
I was rather disappointed with the Viair 400p. (my buddy bought one), I waited. I was glad I did.
I decided on the Smittybuilt 2781.
its CFM rate (5.65 CFM) is twice what the Viair is, and we had a contest to fill a 31"...