This is basically an underclocked GTS 250:
GPU 700 MHz (Normal GTS 250 736Mhz)
Memory 1000Mhz (Normal GTS 250 1100Mhz)
Shader 1850Mhz (Normal GTS 250 1836Mhz)
Expect it to be a touch slower than a stock GTS250 (can't find any reviews, but going by the spec, probably round 7%) and the AMD 4850, while being touch cooler/less energy hungry.
And most importantly, over £15+ (over 20%) cheaper than most GTS250/4850 :)
Edit: No longer on Today Only as reflected on the title, but still cheaper than everywhere else. It's also now a 'Hot seller' (wasn't this morning), so I guess at least a few people went for it :)
Credit to CAT-THE-FIFTH on Hexus for finding this deal.
Delivery is free for for AVForum members I believe. Or active Hexus forum members (T&C applies).