The Lenovo Flex 2 15D has a better storage medium than most comparable spec portable PCs that have been on the market for around the same time as it. This notebook PC has an HDD storage medium, whereas most laptops of this age and spec have an SSD storage medium. HDD is a traditional storage drive which stores the information on magnetic disks. HDD drives are slower than other forms of storage such as solid state drives (SSD) and flash drives.
An HDD storage medium is in fact the worst storage medium amongst all notebook PCs of a comparable age and spec to the Flex 2 15D.
The best storage medium amongst similar types of laptop is SSD.