I am so sorry. You're right. That is actually the "P" model, not the "W" model. There is absolutely no trace remaining on Antec's site of the VP550W in any version.
But you are right. The V2 has a lowered output of only 444W on the combined 12V rails according to a 2010 post on this topic over at TechPowerUp.
As a matter of curiosity, do you have this PSU or are you buying it? If the latter, where from, since not even Antec seems to support it in any shape or form anymore.