Ati radeon 6870 vs gtx 460 ? whos better and why?

ok iam buying a core i5 2500k with a p67 mobo 4gb corsair 1333mhz and a 700 watts psu mushkin and i would like to know wich card is better ? and why? and plz dont tell that in intel procesors ati cards doesnt wok fine..XD tHx