x600 is suppose to be the PCI-Express version of the 9700, except clocked a bit higher. The x600 should fare better then the x600.
I also forgot to mention that you SHOULD get the W3V because I believe the american version has the BEAUTIFUL LCD cover, while the other ones I saw in pictures (the one with the 9700 and the integrated graphics) had a lid that didnt look as pleasing.
Also if your buying the W3V out of fashion, you should also consider the V6V. These new asus models are all fashion models anyway. I was in your shoes the other month and I was going to choose another Asus model, though I opted for my current laptop because I wanted to try Acer and ATI. I'll probably be buying another fashion laptop (like my s5ne) in 6 months.