okay agree with most of the points you made benchmark cannot be given until different manufactures card are bench marked together.
Site reviews of bench marks are highly subjective some manufactures give incentives to write good reviews of them,overall there is not much difference between the 2 cards.
My only point of argument is
the overclockers club of HD7800 graphics card, most of them did not buy HIS cards even though it is cheaper than,msi,sapphire or asus,
this being an elite group of hard core gaming fanatics choose to overlook such a high value for money graphics card(HIS 7870 OC)
why? may be they know something about HIS sales and after service which you or me don't know.