Agreed - the capabilities of a specific mining gpu must outweigh the lost scrap value since one cannot sell it on to the gaming or visualisation markets
Until that time, gaming cards will be the card of choice I believe simply due to their scrap value being taken into account when calculating lifetime ROI
Perhaps another point to add that would be desirable: compact size. The smaller the card the smaller the rig and the smaller the rig the more rigs one can fit into the space - thereby reducing the space a farm takes up (heat dissipation of course would need to remain unaffected.......)
I thought about compact size and while there is some value to that, so far my experience with the Zotac "Mini" line has been that even though I can cram more in, I have to seriously reel in the clocks to keep the temps down, the cooler just can't keep up under full load, it starts throttling on a 8x1070 rig I have.
I had to cut the Zotac Mini 1070s I have down to 70% TDP to keep them from throttling at stock clocks.