First I replaced my 400w mh with a 600w LED that has 3w bulbs. This light saved me almost a hundred watts of power and the girls love it. The density of nodes is almost too tight! And the stems and leaves are hearter.
I was so happy I just replaced my 600w hps with an 840w LED that also has 3w bulbs. I did a lot of research beore I spent the money on these bad boys but its worth it. The girls are happier, my heat issues are almost gone, and I'm using less power!
The key is to get at least 3w led bulbs and as many spectrums as you can afford. And you have to quit expecting something for nothing- a 90w led will never come close to a 400w mh or hps. But a 600w led that pulls about 325 watts will blow away a 400w mh! And as for canopy penetration I see no issues at all- but I wouldn't say the same thing for anything but a light with 3w chips.
I looked at stealth grow and advanced leds but went with a company called Custom Spectrum. Here is the link if your interested.
http://www.customspectrum.com/