So, I was looking at the website for onboard air. The kit for a K5 with a serpentine belt would run about $530. If I were to get this, what kind of performance should I expect? I know you can run airtools, but how well would a half inch impact gun work? How fast would a set of tires fill up? I guess a good comparison would be if you compared to the top of the line 12V jobber from Sears?