The Lenovo Yoga 2 has an HDD storage medium which is better than the SSD storage medium found on most notebook PCs of a comparable type and age to it. 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 actually the worst storage medium amongst all 2 in 1 laptops that have been on the market for more than a year.
The best storage medium amongst similar types of portable PC is SSD.