Well your floros will save you a whole lot more money as the wattage and temps are lower.

But rememebr your value cannot be pressed upon power consumption alone. When you are talking eficiency, you simply need to determine what will yeild the most in terms of Grams per square.

Your HPS will generate far more grams per square that the floros....

I guess you just need to match that against your floros.

1600W of HPS is not that much juice in reality........if you down size the other lights in your house to CFL's you will offset much of that 1600W over a grow season.

20 40W tubes is 800W....where as the 1600 is from the HPS....

Yes your yeild will at least double with the 1600 HPS lights....thereby saving you money from a different direction.