The Asus UX303LA has a better storage medium than most notebook PCs of this age and type. This Asus laptop has an SSD storage medium, whereas most portable PCs of a comparable age and spec 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.
This notebook PC's storage medium (SSD) is in fact the best storage medium amongst all medium processor core notebook PCs that are a comparable age to the UX303LA.
Amongst similar types of notebook PC the worst storage medium is HDD.
Laptops with a better storage medium that might be worth considering include the T420s (£1,388.87) (SSD), or the S540 (SSD) both from Lenovo.