The Zenbook UX305 has an SSD storage medium which is better than the HDD storage medium found on most laptops of this type and age. 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 portable PC's storage medium (SSD) is actually the best storage medium amongst all portable PCs of this age and spec.
The worst storage medium across comparable types of portable PC is HDD.
Laptops with a better storage medium that might be worth considering include the Toshiba Tecra Z40[plb_2252510_price] (SSD and cheaper).