My mics are the AT853's mounted on goosenecks, FWIW. Don't know how much draw the C4's have compared to the 853's, but I definitely think the art box would power them for a good while (i.e several shows at least). I've been very pleased with the art product, and the price was definitely better. Phantom power is phantom power from all I've read / been told. Also, having a battery per channel seems like a better design in my mind anyway. Think of the denecke as levis and the art phantom II as wranglers. You are paying the extra $ for the name, IMO. I have a small rat-shack battery tester that I check my 9v's with before each show (I stopped leaving the bats in the art box after accidentally turning the switch on prior to storage one time) for peace of mind. I would run the C4's with the art box for at least one full show without worry, and then check the batteries with a tester to see if you notice a significant drain.