Gibbo, I don't mean to sound ungrateful, but a few competitors have the Gigabyte Windforce 780 for under £400.
I missed the 7990 offer (partly due to thinking about coil whine and whether I wanted both PCs to be AMD based) and the Gigabyte is the card I'm now considering as it has a decent air cooler but is also reference PCB. A combination I don't think any of your sub-£400 780s have, plus the Gigabyte warranty.
Just have to convince myself that a single 780 is better than 670SLI... (feel free to help out if you want a sale
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