well lol, quoting scratches on the chasis as quality of build? sorry that's just naive and short sighted.
Dell is a big company, so unless their ODM specifically uses different touchpads from latitude to alienware cases I wouldn't expect much difference.
As said above, AW is same price as a 17" xps, because alienware has higher premium (read glowy lights and alien heads), and smaller form factor. As far as cooling being better, I'm really skeptical toward that statement seeing how they have to squeeze fans and heat sinks into 14" chassis vs 17" chassis.