http://youtu.be/r1o1I1zb8gU

This is a side by side comparison of a normal HDD, with a SSD. (Maybe he said it was a hybrid, I forget, but I know he mentions hybrids)

Its not just Load times between zones, but actual game content is effected, mainly larger scale content, such as FATEs, where the game loads a lot of info off the HDD while in combat.

Either way, give it a quick watch, to see how it effects the PS3. (IDK how it would effect the PS4, if it could even be any different from the PS3.)