For me, there were several reasons..I grow in a bedroom closet, my only airflow in and out is the fans in the doorway, and the bedroom ac vent is about 5 feet from the closet entry on the ceiling..CFLs, allowed me to keep a cool temp throughout the entire grow. Im an HVAC dude, so I built my own light fixture with shit lying around my garage. .half the lights I already had and 12 45watt 6500K bulbs for 40 bucks was too good of a deal to pass up..they last forever, safer to leave running on timer when out of town for a couple days and they allow me to play mother nature with different color spectrums which is cool to me. I was skeptical at first, but when I took my first bonghit of the frosty ass shit I grew and instantly was baked way more than any dispensary weed I've smoked in months I feel CFLs serve their purpose well when used correctly.