Has anyone tried LED grow lights for seedlings?

[tomatoguy]

I see these blue and red LED systems advertised as grow lights a lot lately. I can see the advantages; less power consumption, less heat, etc. I wonder, though, if the spectrum would be good for tomato seedlings and if they are as powerful as they are advertised to be. Does anyone have personal experience with these?

I already have a two-tiered system of fluorescent grow-bulbs and Metal Halide light so I'm not looking for advice on getting started. Just looking for alternatives. In other words, I have an extra shelf in my grow box that doesn't have lights.....yet.

mater