Hi guys! I'm considering on either getting a Dell Vostro or Latitude with a 14.1"WXGA LCD or an XPS with a 15.4"WXGA but can't really make up my mind. The Vostro 1400 appeals to me the most currently, followed by the Latitude D630 but there's almost a RM1k price difference between comparatively similar specs. I have these few questions though.

i) Is there a big difference between the 8400M GS and 8600M GS and 8600M GT (Vostro only supports up to 8400M GS while XPS has the 8600)

ii) Is there a big difference between the T7250 and T7300? (both are 2.0GHz but the first has 2MB cache while the latter has 4MB but does it make a big difference?)

iii) what GPU is comparable to the nVidia Quadro NVS 135M used by the Latitude D630? Is it usable for gaming or only good for designing programs etc.

Thanks a lot in advance for the help!