The HP ZBook 17 G2 has a better storage medium than most notebook PCs that have been available for a similar time to it. This portable PC has an SSD storage medium, whereas most many processor core laptops that have been on the market for a similar time to it have an HDD storage medium. Solid State Drives (SSD) store data in semiconductors on a circuit board rather than using magnetic or optical media. Solid State Drives have no moving parts which makes them very fast and reliable.
An SSD storage medium is actually the best storage medium amongst all many processor core laptops that were released more than a year ago.
The worst storage medium amongst similar types of laptop is HDD.