Basically, it's not worth putting 2 cards in sli until they outperform top of the line cards.
Or is it that the performance increase though sli relative to the individual cards is much higher with higher end cards than it is with lower end cards?
Also, wow this is a great community. I literally joined at midnight last night and posted this a while later, and got 6 replies by the next morning. And I have yet to see a single troll/asshole on this forum.