The HP Envy x2 has a better storage medium than most notebook PCs of a comparable age and spec to it. This laptop has an SSD storage medium, whereas most similar spec laptops that have been around for around the same time as 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.
This laptop's storage medium (SSD) is in fact the best storage medium amongst all notebook PCs of this age and type.
An HDD storage medium is the worst storage medium amongst similar types of laptop.