I dont know why its an either or debate when you can combine the 2 spectrums for the ultimate. In a staggered pattern. Cmh for the more plant friendly sectrum and hps to give up that chunky high calyx to leaf and weight. If you have Gavita de fixtures..roll with the new 630 cmh de. If you have 600 mogul socket hps...roll with the 315 lec lamps from Sunlight Supply. If you have 1000 watter moguls...roll with the double bulb 630 cmh. Does this makes sense or am I all wet? I have seen people replacing whole rooms with 315's and 630' cmh lamps and killing it though. These growers are yielding 12 to 16 ounces per 315. Thats frikin amazing. And saving huge on the electric bill. I know a guy that has 4 315's from Sunlight Supply and hes getting 50 to 60 ounces of trimmed dried buds. Thats ALOT from 1260 watts. Something he could never do with a 1000 watt mogul socket hps.