I've been running the green machine 9 watt for about 2 months in my evo 13.5, so cool to see that I am not alone.
I picked it up from Petsmart for about $32 (maybe less). Same chamber, but mine does not stick out of the chamber like yours since I don't have enough water in chamber 2 for that. I just shove it down.
I don't agree that the water stays in the same chamber. I am running a Radion XR15 G5 on mine and the lighting is amazing... but mine is not a QT/staging tank, so different use.