In bschool, long battery life and light weight = KING....
Screen size? It's a tradeoff I am willing to take to save me some shoulder and back pain.
Your bag is ridiculously heavy already, plus you don't wanna carry your AC adapter everywhere. (Sometimes, even when you carry it, it doesn't mean you can always find a place to sit where you can plug it in somewhere....)
Trust me, something like X series or other mobile laptops are worth the investment.
Also, get a decent warranty. My VAIO stopped working last week. OS wouldn't start no matter what. Spent 1.5 hrs on the phone with tech support on the other side of the world....and he made me open up my laptop and remove hard drive and other stuff....
2 things crossed my mind during that time:
1) How in the hell do they expect average laptop user to do this over the phone?
2) If my laptop wasn't broken before (opening it up), it definitely is broken now....
After 90 minutes of that non sense, they finally transferred me to someone who took my info so they can send me a Fedex box so it can be repaired. Needless to say, I am using the Yale issued Dell Latitude for the first time since the Orientation week....and this thing is not 2.7lbs....