The Lenovo Flex has an HDD storage media which is better than most laptops of this age and spec. Most portable PCs that were released more than two years ago have an SSD storage media. 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 portable PC's storage medium (HDD) is actually the worst storage medium across all portable PCs that have been around for a similar time to the Flex.
Across similar types of portable PC the best storage medium is SSD.
Notebook PCs with a better storage medium that might also be worth looking at include the Toshiba U920t (SSD) which also has a higher rating.