Marketing terminology is always a tricky thing to decifer. I don't think anyone has been able to make a reflective medium that increases the light output, if anything a better reflector looses
less light than an inferior design, or focuses/directs it differently. You also have to look at what people mean by 2WPG, for example, is that intended with or withuot a reflector? I think it's safe to say we mean with a reflector. As much as I praise the ahsupply kits, they are great from every perspective, the ballast is awesome, the end caps are quality and their reflectors are very focalized, their marketing hype about this reflector is worded to give the impression that it actually increases light output. I don't see it loosing any more or less light than a flat reflector honestly, I just see the light being concentrated into a narrower beam. Meaning that if you put a lux meter in the central focal point you will likely get much more light there than with a flat reflector which would scatter the light over a wider surface area. There is also likely less restrike but these are minor things.
Conclusion is don't use the reflector in your calculations of WPG, as long as you have a reflector just use the bulb's rated wattage for this calculation. The WPG rule isn't precise enough to accomodate small changes due to reflector design. Where you do want to give reflector design importance is when it comes to light spread. The ahsupply reflector concentrates light into a narrow area, meaning it would light up a deep tank far better than a flat reflector, or be very useful in suspended PC lighting where you want to keep as much light out of the surrounding room. A flat reflector on the other hand would prove a better choice in a tank that is not so deep and specially if the bulb/bulbs don't cover much of the surface area of the tank. For example a 20g long tank with a single 55W PC would likely benefit greater from a larger spread of light than a narrow one. Otherwise you end up with a lot of light directly under the reflector and little in front and behind it.
It's a great reflector and it concentrates the light into a narrow surface area, something you can modify too by bending the reflector out to give a wider spread if needed. For the price and quality however, ahsupply remain on the top of my list, but the reflector doesn't have any magical properties to my knowledge
Hope that helps