Iv'e got one of those and i think it's good for a one light grow, you are sacrificing some light compared to a straight up 1000watt hortilux hps, but your gaining in the blue light spectrum. i use mine for veg and the first week or two of 12 hour days but since i also have a hortilux hps i switch to it for most of flowering. the bulb i really like for veg is the blue halide special. that bulb makes my ladies the happiest iv'e ever seen. jc
hortilux 1000 watt HPS gives the most light for a single lamp, but some say if you go digital you can burn 2 600's for around the same cost, and that's gonna be even better, i went for a couple recently and they burn hortilux lamps without a proplem, the light looks a bit brighter than the core and coil ballast that next to it. any others like to chime in.....jc