The HP ProBook 650 G1 has an SSD storage medium which is better than most medium processor core laptops that are a similar age to it. Most laptops of a comparable age and spec 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.
An SSD storage medium is in fact the best storage medium amongst all portable PCs that are a comparable age to the ProBook 650 G1.
Amongst comparable types of portable PC the worst storage medium is HDD.
We think you might also be interested in some of the other portable PCs that have an SSD storage media currently available including the DELL Latitude E6430 which is cheaper.
If you are looking for a portable PC with a better storage medium then you might also want to look at the Lenovo L440 (SSD), or the HP ProBook 640 G1 (SSD).