Turbo Boost becomes the deciding factor that gives the Dell laptop a slight edge in CPU performance even though the Asus uses a newer Intel processor. Even so, the ZenBook carries a few other advantages to make it worth considering especially in regards to price and storage.
https://www.notebookcheck.net/Dell-XPS-13-vs-Asus-ZenBook-UX333FA-Kaby-Lake-R-can-still-outperform-Whiskey-Lake-U.387831.0.html
Very disappointed that ASUS is stubbornly sticking to proprietary-only charging.
I found myself in a hotel recently, having forgotten the charger for my laptop. Fortunately, I found that it supported USB charging (as well as proprietary). It was a real life saver.