Why SSD upgrades?

Solid State Drives vs Mechanical Drives"Did you know the benefits of replacing the mechanical hard disk drives of older PC's and Macs with solid state drives (SSD's) will significantly increase the speed of your PC?  SSD upgrade will not only give you faster performance (10x faster), they do not produce any additional heat contributing to rise in internal temperature of the system and performance is not affected by rise in the surrounding ambient temperature."