The X1 Carbon has an SSD storage medium which is better than the HDD storage medium found on most notebook PCs of a comparable age and type to it. 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.
An SSD storage medium is actually the best storage medium across all comparable spec notebook PCs that have been available for around the same time as the X1 Carbon.
The worst storage medium amongst similar types of notebook PC is HDD.
If the storage medium of this Lenovo portable PC is too bad for you then you might also want to look at the DELL Latitude 12 E7250 (SSD).