Coy, with reference to your WPG-remark.
You should take into account that the rule is based on T8-tubes. Your lights are of a newer type that is far more efficient in combination with other factors (for example) that are important:
Bulb (clean, quality)
Reflector
Cover on the tank (the 'glass' cover over the water)
Water-quality (clean and clear water, your filter-quality)
Ambient Light Level in the room where the tank is located (My tanks are outside, they don't get direct sunlight but the ambient light is enough to have the tank growing like crazy with only 1 Watt p/Gallon, T8's)
Now, I think most of us agree that you've reached the kind of top-level setup only enjoyed or reached by few. In part (I think) that is because you are using top-quality substrate, lights, reflectors, filters, power-supply for your lights etc. (there's also a tremendous amount of preparation, determination and patience involved on your part, for which no money that can value that), but all this will help you reduce your WPG-value due to a higher upfront investment.
I'd like to compare that with an electric car. You'd pay more for the electric car due to its very expensive batteries, but the car pays itself later due to lower 'petrol' cost...
The conclusion is still the same though, don't up your light if you're happy with how it looks and you got all your plants growing as you'd expected.
My 2 cents.