I'm comparing the cheapest to the cheapest, if we want to go with the SC or OC versions of the GTX780 then we can add another £40-£80 to the price. For reference, no the Lightning HD 7970 is not worth it for an extra £120. It is poor value for the same reason a GTX780 is poor value.
On that basis though a 7970 is poor value when a 7950 is £120 cheaper, a GTX680 is poor value when a GTX670 is £100 cheaper, where do we draw the line?
