well....I put em on, and was like..these arent bad, but theyre lighting up half my room. So I took a piece of 3/4" pvc and cut it in half lenghtwise and used it as a reflector...now theyre too bright to be moonlights. Although they actually do a pretty good job as actinics, althought once my MH's kick on, htey dissapear.
I did some research, and these things can put out in the range of 50 lumens per watt, which is pretty impressive, considering that MH puts out aroudn 100, and fluoros put out around 15 if I remember correctly.