So can ya'll catch me up real quick on the current cmh technology? First off, are there some brands that are way better than others, or are all ballasts pretty much the same, and the difference is in the lamp? What about vented hoods, I don't really see those much with 315w setups, not necessary? Finally, how does the 315w cmh compete with a 600w hps, is it really a close equivalent? I run a 600w hps, and bought a 400w mag ballast a few years ago, and ran a 400w Philips MasterColor Retro White lamp (now discontinued), and it didn't quite keep up with the 600w hps, so went back to hps.