Should I get a Lenovo X1 Carbon or Lenovo t440s?

I'm a fan of lenovo and love their computers. I don't have a problem with their recent changes with the trackpad and keyboard. I'm a computer science major and what to get a light and fast laptop to complement my workstation. I'm stuck between choosing the X1 Carbon or the t440s.

Budget - $2000
Preferred Weight- Around 3 lbs. Basically something I can put in my backpack easily and walk for a long period with.

Here is my dilemma, the t440s has really nice keyboards and seems to be durable. However, it weighs around 3.5 lb without the secondary battery. On the other hand, the X1 carbon is thin and light, but has a weird keyboard layout. I'm further concerned by the adaptive keyboard strip which might be a nuisance since I do use the f keys quite a lot, especially programming.

Also, the battery I've heard is great on the t440s while the X1 carbon charges really fast. Furthermore, I think that the X1 Carbon looks awesome whereas the t440s looks pretty plain.