I mean for christ's sake I've got a £6000 cat.
Is that all the wife is worth then?

Possibly getting 1 myself to get the most out of my 120Hz monitor, may end getting a 2nd 680 or possibly going for a 690. Prices and benches will decide it for me mostly - just never been keen on SLI with the scaling being hit and miss and micro-stutter (I want smoothness damnit, not jittery ***p!)
All i can say is that the 690 does not suffer from any microstutter and scaling issues.
Those are issues of the past with old dual cards and immature driver support, The 690's design changed all that as you can read from the many reviews that was posted at time of release.
As for SLI 680's, again no issues and even if there are they are very minimal.
Also nvidia inspector SLI profile/AA custom flags are out right away as soon as a game is released.
Bookmark this very important thread!!
http://forums.guru3d.com/showthread.php?t=357956
Theres tons of profiles in here regarding almost everygame out-there powerful enough to utilize 2 gpu's.