Yes it really works!
And you MUST have an electronic ballast, a magnetic ballast will overload and then you would have problems.
The lights do run a little hotter, but less than VHO's and not so hot that it causes a problem or tank temp problems.
I don't see the ballast in your picture, I'm betting on electronic because magnetic ballasts are pretty big and heavy...but check close to be sure.
FYI...you can even overdrive most bulbs by as much as 3x or 4x! Simply connect a 4 lamp electronic ballast to one lanp and you have a 4x overdriven lamp...bulb life will diminish quite a bit at 4x, but at 2x or 3x you hardly notice the difference.