i don't really know but the X1400 scored around 1800 in 3dmark05 and the 7300go scored around 600 in 3dmark06 which is pretty low...i know its not a direct comparison but...=
if you take the X1300PRO desktop version which scores ~2500 in 05 and ~1200 in 06...and you make a proportion for the X1400 it makes it around 850 so it should be faster than the 7300go...
Back to the 7300go, it should do fine for BF2 at low, i think you can try med but don't except alot from that card.