Got my 8x16 LED boards from http://rgb-123.com
this week, and given how bright they are I wondered how visible it would be in direct sunlight. In this video there's slight shade on the right hand side of the board just to show that the thing is working.
To the naked eye it's much more visible than this, but the camera isn't showing it or the colour too well. I don't think it'll be good for 'read at a glance' signs, but as a light display it's eye-catching enough. Fully on it draws about 3A at 5V.