The Asus is a full pound or 40% heavier than the X1 Carbon (~2.5 vs 3.5lbs).
The Asus has a dedicated GPU which is nice if you ever do more than office work on it.
The Lenovo has a better PCIe x4 SSD with ~3 times the speed of the one in the Asus. Unless you buy the 1TB model Asus is only using x2 PCIe SSDs - it won't be slow, but they are cutting corners there.
Processor speed difference between the two is in most cases less than 10%, you will not notice anything there one way or another.
Battery life will be better on the X1 Carbon, but if you're docked that is a moot point.
You're getting better surrounding hardware in the Lenovo (keyboard, chassis, trackpad etc.) and also paying for the fact that it's a lot smaller/lighter. The 15" Zenbooks are good entry/mid level value though and are relatively compact for a 15 incher.
Either will suit your needs just fine given the intended usage - again it comes down to screen size, weight, & chassis quality for the most part.