So I got the cateye and I am quite impressed with it. I do think it might be DOT approved as I compared the markings on it to that of the stock tail light and they are quite similar. Both the DOT markings and the E marks.
To whomever asked earlier yes there are 5 or 6 white LEDs out the bottom that are for lighting the plate. There is a gasket behind the lens to help seal out water. It is also very nice and thin.
I set them up and took a couple of pictures side by side. Now I know everyone wants them out in sunlight at 100 paces but I wasn't in the mood to try to get it set up outside. Although we were in a thaw I wasn't up to a winter experiment. Sorry
One thing I will say is the stock tail light is very directional. Meaning it fades fairly quickly if you are not directly in line with it. I took these pictures head on with it so that it was at it's brightest point. Here is what we have.
This is the running light.
and here is the brake light.
It is going on my wife's bike so I am sure I will have plenty of miles following it to beside if I need to add any extra to it.