Hi, Im thinking of upgrading my ageing 6600GT but i'm not sure which upgrade I should go for. I was thinking about getting the XFX GeForce 7800GT Extreme Edition 256MB GDDR3 for £176 but I have also seen the XFX GeForce 7900 GT 256MB GDDR3 for £235. Would it be worth getting the 7900 over the 7800 in terms of the price difference? Would the boost in performnce from the 7900 be worth more than the price difference?