Your PAR theory has little relevence, if you want to spend the money on 8 cfls and fixtures go for it, 1 400wtt hps is 10,000 more lumens, now when you talk about buying new bulbs, i would rather spend the money on one bulb ever so often then 8 cfl's, dont be fooled many the cfls burn out too. You thinking way to far into this, a new bulb is 80 bucks, thats nothing compared to what you get. Im not making any assumtions, if you read up on any of this, there have been grows under cfl and hps, the hps yeilded more then double. if you took the time to look you would see. Im not ever sure why your looking into par levels, radiation?? what are u worried about and so skeptical on. Find a light that suits you. buy a cfl if you worried about heat, get enough lumens so you have a nice yeild. If heat isnt a problem then a hps will be cost effective and easier to use. Cfls are not new, and have been talked about more then you can imagine, just cause your new dont assume i am assuming, expecially on something im activly part of everyday. You want an honest opinion on the matter, so you get it. Dont be upset cause people dont care about PAR becuase its irrelavent, or of no intreast to others. I mean people who make these bulbs take that into account so we dont worry about it. I dont know what info your looking for on PAR but i assure you its a waste of time looking into it. Im still wondering what your question is cause the thread is hid vs cfls, i will say right now a hps light will do better then any cfl efficiently. not to mention the spectrum is perfect on hps's.