4 years ago I had a few grows with CFL, the first 3 pics show the results of 6x42 watt + 4 X 24 watt CFL for a total of 348 watts on 4 plants, the last 2 pics show what a 400 watt HPS can do with 8 plants.
Granted the CFL grow was like grow #4 and was fairly inexpensive and now were on like grow 25 with plenty invested. the CFl gave me 50 grams after 60 days of veg and 82 days of flower. The HPS yields significantly more, usually in the range of 400-500 grams and thats after a total of 14 days veg and 65 days of flower. Hydro helps that timeline probably more than the lighting does, but the yields are many times more dependant on light quality and strength.
Hey CFl works, im proof of that, but HPS is king of grow lights when it comes to yields and is the most bang for the buck.