The Lenovo X1 has a better storage medium than most similar spec notebook PCs that have been on the market for a comparable time to it. This portable PC has an SSD storage media, whereas most comparable spec laptops that were released more than two years ago have an HDD storage media. 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 in fact the best storage medium amongst all medium processor cores notebook PCs that have been around for around the same time as the X1.
An HDD storage media is the worst storage medium amongst comparable types of portable PC.