Basically when you look at the math... the number of photons in the useful spectrum for plants... HPS is around 30-40%, MH is also around 30-40%, CFLS are 60-80%(~5000K best imitates actual daylight, 2700k/3000k and 6500k accord for red/blue shift). HID lamps lose their luminance quicker than floros due to the extreme heat, but they all lose luminance over time. I'd guess 6-8 vs 12-15 months, not much little longer.
Basically 'an expensive' 220 watt CFL can match 'a cheap' 400W HPS or MH. And it'd take 'a cheap' ~368 watt CFL to match 'an expensive' 400W HPS/MH. 148 watts... somewhat substantial difference. For example, 16 23wt CFLs spaced evenly in 1 sq ft box grids among a 4'x4' would decently light at least 1 foot downward, with proper reflector(s) this would increase 30-40%. This is the same area a 400 watt covers, but with much more even light distribution, while less center intensity.
This is somewhat obvious... constant 1100 degree C HPS spark = MORE HEAT vs a much cooler floro tube = MORE LIGHT.
*cheap refers to HID/CFL 30/60%.. non-grow light/generic/wrong spectrum/just plain old and used
*expensive refers to HID/CFL 40/80%.. grow lights/specialty lights/ideal color temps and quality made
I've seen the PAR of plant specialty LEDS rated around 90%.
T5's are also PAR 80-90% efficient(another form of floro).