The LifeBook S904 has a better storage medium than most notebook PCs of this spec and age. This notebook PC has an SSD storage medium, whereas most notebook PCs of this age and spec 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 across all portable PCs of a comparable age and type to the LifeBook S904.
An HDD storage medium is the worst storage medium across similar types of laptop.
Portable PCs with a better storage medium that might be worth looking at include the T420s[pl_48433_price] (SSD), or the X1 Carbon[pl_2432329_price] (SSD) both from Lenovo.