The Lenovo Flex has an HDD storage medium which is better than most portable PCs of this age and spec. Most 2 in 1 laptops that were launched around the same time as it 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.
This laptop's storage medium (HDD) is actually the worst storage medium amongst all comparable spec portable PCs that have been available for a similar time to the Flex.
Amongst comparable types of laptop the best storage medium is SSD.
If you would prefer a portable PC with a better storage medium then you might want to consider the HP 13-r100dx ($850.46) (Hybrid-HDD).