5870 will be more powerful if you go just by specs , recent leaks suggest the same , 4870x2 has scaling issues , 5870 will not , plus its unclear how much the design was changed in rv870 .AMd really delivered this time , everyone wanted the same transformation they had from 3xxx to 4xxx and we seem to be getting it , would be nice to see what NV has but at this point it will be hard for people not to jump the ship considering ATI has everything they wanted.