Dell XPS 14 or 15 (Sacrifice CPU or Resolution)?

So I'm considering either the new Dell XPS 14 or the Dell XPS 15 laptops

Both come with the NVIDIA 420 video card which appeal to my very casual gaming and HD content viewing.
FYI - I am an HD junky

After personal configuration, they both roughly come to be the same price, however....

I'm more or less faced with the following decisions:

A) Dell XPS 14
- Core I5 460
- 14" 720p display
- 4gb RAM
- 500gb 7200rpm internal drive
- free 320gb mobile drive

or

B) Dell XPS 15
- Core I3
- 15" 1080p display
- 4gb RAM
- 320gb 7200rpm internal drive
- no free mobile drive

I know it comes down to personal preference, but I guess it really comes down to what I want to sacrifice: CPU or Display Resolution

Any thoughts? What would you sacrifice?