The Transformer Book T200TA has an HDD storage medium which is better than the SSD storage medium found on most portable PCs of a comparable age and type 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 similar spec portable PCs that have been around for a comparable time to the Transformer Book T200TA.
The best storage medium across similar types of portable PC is SSD.