Coolermaster are rebranded in the same way Gigabyte PSU's are made by Channel Well Technology. Antec and Tagan build their own PSU's I think also.
To be honest, I don't see the point of buying something that's been re-branded, might as well pay that little bit extra and get the proper unit from the original manufacturer. Enermax & Seasonic PSU's are highly regarded because they make their own damn units, their not just plastering a stupid logo on something someone else made and because of that, they actually know about Power supplies, whereas Coolermaster et al have no expertise.