The ENVY 15 has a better storage medium than most laptops that came out around the same time as it. This notebook PC has an SSD storage medium, whereas most medium processor core notebook PCs that have been around for a comparable time to it have an HDD storage medium. Solid State Drives (SSD) store data in semiconductors on a circuit board rather than using magnetic or optical media. Solid State Drives have no moving parts which makes them very fast and reliable.
This portable PC's storage medium (SSD) is actually the best storage medium amongst all similar spec portable PCs that have been on the market for more than two years.
Amongst similar types of portable PC the worst storage medium is HDD.
If you would prefer a notebook PC with a better storage medium then you might also want to consider the T420s (£1,388.87) (SSD), or the S540 (SSD) both from Lenovo.