According to me the best features of this phone are:
5.2" screen with 1080p resolution(424ppi)
Android 6.0 Marshmallow
2GB of RAM, Adreno 418 GPU; Snapdragon 808 chipset
12.3MP camera with laser autofocus
2160p(4K) video recording
Good Fingerprint reader
USB Type-C
Things I dont like:-
No card slot
No OIS for the camera or wireless charging. Optical Image Stabilisation is missing in this nexus device.
Plastic Back Panel(Does not feel premium)
Overall Lg Nexus 5X is a very good phone for its price, and the best thing is that you will be getting Updates from google much faster than any other devices.