question about LED lights

what is the word about led grow lights, like the 90 watt ufo packages.
how much light do they really put out? do you have to use them with other lighting?
are these not the same lights as the red white and blue outdoor christmas lights?
any thought on this...
I was thinking of using LEDs. and what is the difference on say 400w hps output compared to the 400w led output and energy consumption?
thanks in advance. i will put up pictures when i come up with a good setup

in short, LED proved to be a failure in flowering decent bud. if you want to grow something good, HPS is still the best. maybe induction or plasma or even LED light will be the future, but up till now, HPS is the way