Compare ati 4330 nvidia GT 330M

i am buying a dell laptop
basically i am confused between the vostro 3700 and inspiron 1764 i5 and 4gb ram
but the grapic card the vostro offers a nvidia gt330m and ispiron a ati 4330 mobility card
and also vostro gives the extra processor speed edge

i am currently using an ati 4650 graphics card which i think is working amazing

please tell me which to go for
both are for the same price and almost the same config except the graphics card