The ZBook 15 has a better storage medium than most many processor core portable PCs that are a comparable age to it. This HP portable PC has an SSD storage medium, whereas most many processor core portable PCs that were released one year ago 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.
This notebook PC's storage medium (SSD) is actually the best storage medium across all notebook PCs of a comparable type and age to the ZBook 15.
The worst storage medium across similar types of notebook PC is HDD.
We compared all the other laptops that have an SSD storage media to this laptop and we think the ThinkPad T540, and the ThinkPad T540 both from Lenovo or the DELL Precision M4800 which is cheaper is also worth considering.
If the storage medium of this many processor core notebook PC is too bad for you then you might want to consider the Fujitsu Celsius H730 (SSD).