Laptop for Engineering (Lenovo T400/500 vs. Dell Studio XPS 13/16)

I need to buy a computer for when I start college in the fall. I am going to be an engineering student at UVA. It's between the Lenovo T400/500 (13" vs 15" ) and the Dell Studio XPS 13/16 ( 13" vs 15" ). The Lenovo's are identical to each other besides the screen side, while the Dell's have different video RAMs (256 MBs vs 512 MBs).

Comparing the two brands: Lenovo has a higher processing speed than Dell (2.8 GHz vs. 2.53 GHz), and the larger Dell has more vRAM. Everything else is pretty much equal (although the Dell is a bit nicer on the eyes with a higher quality screen and design, while the Lenovo appears to have better battery life).

Do you think it'd be better to have faster processor or more vRAM if I'm doing all of the engineering stuff (AutoCAD, etc.) plus some gaming (mostly strategy, so nothing too intensive, but I would like it too run as good as possible)?

Lenovo:
http://www.uvastudentcomputers.com [...] 3BBEDFCBA8

Dell:
http://www.uvastudentcomputers.com [...] 3BBEDFCBA8

Engineering Requirements:
http://infotech.seas.virginia.edu/firstyear/

Thank you. That's actually where I am leaning. Now I'm trying to decided between the Lenovo T500 and a 15" MacBook Pro. The main issues I see with the MacBook is some compatibility issues with the engineering software (even when running Boot Camp) and the decreased battery life in Boot Camp while running Vista (because of power management problems).

Just out of curiousity, what type of applications use "tons of filtering"?

No, that's helpful becuase I might do some gaming. What sort of gaming performance could I expect out of the HD 3650 256 MB?

For engineering (and really any scientific work that means something...) there is no alternative to a PC. I wouldn't even consider a mac.

Lenovos are solid machines, and I see them in labs often.