The Lenovo Flex 10 has an HDD storage medium which is better than most laptops that have been available for a comparable time to it. Most 2 in 1 laptops that are a comparable age 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.
An HDD storage medium is in fact the worst storage medium across all 2 in 1 laptops that are a comparable age to the Flex 10.
An SSD storage medium is the best storage medium amongst comparable types of portable PC.