wait, 100w equivilant cfl's are only $1 ea in Connecticut, is that some sort of government rebate program or social welfare? Damn, what store is this - I need to grab some!
the 23 watt cfl I have (claims to replace a 100w bulb) outputs 1600 lumens, that's roughly 70 lm/w. The best rated cool white rebel is 180 lm @ 2.38w (700ma * 3.4v) which is roughly 76 lm/w. To match the output of my $8 CFL, I'd need 9 rebels, at $6.60 ea that's $60. I think I'll stick with compact fluorescent for now. It is good to see the numbers are getting better, but lumens per watt isn't the metric the public will judge new lighting technology by. It's lumens per dollar:
rebel = 3.6¢ per lm
cfl = 0.5¢ per lm
The reason Edison is still rich with his hot-wire bulb = 0.016¢ per lumen ... that's right, $0.00016 per lumen (figuring 25 cents per bulb)
edit:
oh, don't forget to include energy used by the driving circuitry - cfl's have very efficient offline smps powering them. the same technology is just now becoming available for leds. running leds using resistors or linear regulators puts their efficiency numbers back in the stone age with the hot wire bulb.
edit2:
if your heatsink didn't even feel warm, then you have a problem with thermal coupling. most "star" type leds have a rather high thermal resistance, although it's better than the olden days. new ceramic composite leds have a much lower resistance (rebel, ostar, lamina) - they're the ones you can really push. you need a laser IR thermometer or a well placed thermocouple to really measure the junction temperature - lumileds has some data about this in their thermal management white paper.