The HP Pavilion x360 has an HDD storage medium which is better than most comparable spec notebook PCs that have been around for a similar time to it. Most laptops of this age and spec 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 2 in 1 laptops that have been around for a comparable time to the Pavilion x360.
Across similar types of portable PC the best storage medium is SSD.
It may also be worth also looking at one of the other portable PCs that have an HDD storage media currently available including the Asus TP550LD, the HP Pavilion x360 (£315.98), or the DELL Inspiron 11 3147 which has a better Rating.
If the storage medium of this 2 in 1 laptop is not good enough for you then you might want to look at the Twist (Hybrid-HDD), or the Yoga (£774.46) (HDD+SSD) both from Lenovo or the Acer Aspire SW5 (HDD+SSD) which is also higher rated.