The Lenovo Flex has an HDD storage medium which is better than most 2 in 1 laptops that have been on the market for more than two years. Most notebook PCs that have been around for a similar time to 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 notebook PC's storage medium (HDD) is in fact the worst storage medium across all 2 in 1 laptops that were released around the same time as the Flex.
Across comparable types of notebook PC the best storage medium is SSD.
There are a number of other laptops that have an HDD storage media currently available that you might also want to look at including the Flex 15, or the Yoga both from Lenovo which is cheaper.
Portable PCs with a better storage medium that might be worth looking at include the Toshiba Satellite U920t (SSD), or the Fujitsu Stylistic Q702 (SSD) which is also cheaper.