The Pavilion x360 has an HDD storage media which is better than the SSD storage media found on most 2 in 1 laptops that have been around for a comparable time 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 media is actually the worst storage medium across all 2 in 1 laptops that were launched around the same time as the Pavilion x360.
The best storage medium across similar types of portable PC is SSD.