The Transformer Book T300FA has an HDD storage medium which is better than most comparable spec notebook PCs that are a similar age to it. Most similar spec notebook PCs that have been around for around the same time as 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 actually the worst storage medium across all notebook PCs of a comparable spec and age to the Transformer Book T300FA.
The best storage medium amongst comparable types of portable PC is SSD.