m17 has far superior... FAR Superior horsepower with the exception of grfx card.
Thats not to say it has the inferior grfx solution, Im not sure how the ATI's stack up against NV's top offering, but as cpu games aare grfx card bound, generally the better grfx card solution will be the best bet.
Keep in mind though that the m17x is built on an aged Santa Rosa platform and even if you get a better benchmark now (it prolly wont be by much) the m17 is abuilt on a year newer platform and has much longer to grow(upgrade grfx cards) than the santa rosa based m17x.
althought the m17x beats the pants off the m17 in looks!