The CPU's are the same; one quotes the base clock, the other quotes the turbo clock.
Also, the 6755G2 GPU in the second one is simply an asymmetric crossfire of the integrated graphics card and the AMD 6750M. The first one says it has a 6750M too, though. It looks like they chose not to implement the asymmetrical crossfire in the first one...
Other than that oddness with the GPU's, they look identical. The asymmetric crossfire might help, and it might not; I'm unsure which. To be honest, I'm thinking go ahead and get the one with the crossfire enabled if you can afford it. The crossfire will help in newer DX10 and DX11 games, but it'll actually hurt the overall performance in older DX9 games. With developers finally moving to DX10+ (kind of), I'd go ahead and spend the extra money.
Just my two cents.