Looking for a new laptop for school

[JLuo]

Hey guys, I am looking for a new laptop, ultrabook preferably, for school. Budge is under $1500+ USD. I am looking for something that's
-Light
-Long batter life (~7hrs)
-Run autocad & 3D modeling programs

I already look at a few. 
-Acers S7 http://www.ncix.com/detail/acer-aspire-s7-392-5626-core...
-Zenbook
-Maybe, Samsung ATIV 9?

Don't really need a gaming power-house, I already have a decent desktop at home. Since I commute to school every single day (two hrs each way), I don't want to haul a heavy ass laptop with me, and in addition with my textbooks. 

I am looking for your guy's opinions and recommendations. And thanks in advance!

[JLuo]

I doubt I will be doing some serious CAD work since I am still only an undergraduate, but what would you recommend? Just need something for every day uses. 

[MTROB]

Have you looked at the Lenovo X1 Carbon? https://lenovo.com/us/en/laptops/#/?facet-1=4&facet-2=2&facet-5=4

[JLuo]

I did but then if i make it have the same specs as Acer S7, then it will be even more expensive. 

[JLuo]

What do you guys think of this one then? 

http://www.ncix.com/detail/asus-intel-core-i7-4510u-8gb-a6-98212-1388.htm