I was partially mistaken. The Corsair PSUs are 90% efficient, not 90+ so they are the same as Enermax then. And Seasonic produces OEM power supplies for these companies. Often times Seasonic does not produce an exact model of their own. In fact looking around Newegg I did not see any identical models when comparing with the Corsair and Seasonic offering. I did not check PCP&C or Antec, though.
Also, they do not produce every PSU line for Corsair, Antec, and PCP&C, just quite a few. Channel Wells produces at least 3-5 models of the Corsair PSUs so saying (seasonic) every time would not be correct. Channel Wells also produces many Thermaltake PSU's including the 750W I have seen you use before so if you want to be technical you should start saying (channel wells) as well where it is due.
Just like Foxconn makes motherboards for many companies. I'm just saying that regardless of who makes them, you should call them only by the company that sells them because the OEM does not always have identical or better options. Foxconn for example has a very limited number of motherboards produced under it's name anymore.
And yes, Rosewill is a Newegg house brand kinda like Insignia is a Best Buy brand.