As luck, or possibly a little diligence, would have it, Tom's Hardware has a recent article on this ...
http://www.tomshardware.com/reviews/...alit,2096.html ...
Seems there can indeed be a difference, as different licensees may use different cooling etc etc. I don't know how the GeCube version ranks. If anyone finds anything, maybe they could post here. edit/add: It's bad enough figuring out which vidcard you might prefer as between ATI or Nvidia, or between card model XYZ#, but then to have to figure out the best choice as between same model ...
@Dowly. Cheers, yup I noticed you were talking about it ... didn't want to hijack your thread so figured I'd post separately.