IMO i dont think it matter on the type of light you use. the only reason ppl get good results with HID is because anyone can do it. you dont have to worry about placing the light close or or using so many lights. you just plug it in and hang it. Its all about light penetration. I think that if you had enough cfl's you could equal and hid. Now thats gonna take a hell of a lot of cfls mind you. by the time you get that many cfl's you are going to actually saving money if you bought the hid. HID's might be expensive, but think about everything that you have to buy for a CFL setup. First you need the bulbs. They might be cheap, but they add up real fast, by the time you get 15 or so in there you probably already spent $25 or so, no you might want some y splitters. These are about $2-$3 each. So to make an even number lets say you had 16 bulbs. So now for 16 bulbs your gonna need 8 splitters, so thats $16 minimum, if your lucky. So now you've spent around $40 and you still have to wire these bitches somehow or plug them into a power bar. if you plug them into a power bar now you gotta buy 8 of those socket plugs at $2-$3 a piece, another $16. Now we are at $56 and we havnt even gotten a power source yet. If your the DIY kinda guy, you could go out and spend that same money and make your own hps ballast and maybe even get a bulb. So you tell me what sounds better. If you can get rid of the heat, use hps of course. If you cant deal with the heat somehow use cfls.