The ZBook has an unusual design aesthetic that forgoes modern sleek lines for something more muscular-looking. While it's not really rugged, it's designed to be more durable than a typical consumer detachable.
HP and Wacom worked together on the EMR stylus -- that means no batteries -- which supports 4,096 levels of pressure, tilt and rotation, and feels nicely balanced. It's only got a single button on the barrel though, plus the eraser, which makes it impractical for some 3D work. And you can't use Wacom's styluses with the x2.
HP targets Adobe Creative Cloud users with the laptop; it comes with the Creative Cloud app preinstalled, and the company sells the x2 in preconfigured models in the US that are sort of optimized for specific applications. For instance, the $2,700 Photographer config is supposedly for using Photoshop and Lightroom, but there's no reason a Digital Artist needs a lesser $2,280 system for those applications plus Adobe Illustrator. I'd ignore the "helpful" categorizations while shopping.
It doesn't charge through USB so it has a dedicated power connector. There are two USB-C/Thunderbolt ports, an HDMI connection and a USB 3 Type-A. There's also an SD card slot and a fingerprint reader.