this can actually be a pain ....
It does work .. im using a 2 led version that he sold 6 years ago ..
others on the board got units that didint work so great ....
Personally id like to see a time based version.... because if a slow cloud moves in .. the redrok will try to point to the brightest point in the sky(not where the sun is) , based on visible light, and corect me if im wrong(and im sure some one will) i think cheap solar pannels like the UV end of the spectrum more. hence, staying pointed at the place where the sun is, can get power even if the sun is partially blocked - redrok will point away from that point in the sky, then track back to it once the clouds have moved on.
A time based tracker will not care if it is a rainy day, or 102deg summer day.... it will always be pointing at the sun.
PS. im on IRC now.