I got a Viair 200P and am going to hardmount it. The sucker pumps out about 50% more air than the ARB.

I prefer the compressor setup because you are virtually unlimited (given the compressor doesn't die) in the quantity of air you can put out.

I've suffered multiple annoying tire leak issues in Baja and I was glad I could keep airing up every 20 minutes or so along the 90 mile trail. If I had CO2 and ran out, I'd be in a wee bit of trouble.