Just bought an SSD

[Pseudopsia]

HDD vs SSD is night and day difference during load times. Install times will be faster if installing from SSD, if you're installing from blu-ray/dvd you won't notice a difference. After loading general gameplay won't be any different. Edit: you can get stuttering during game play with a HDD if it's loading data during gameplay, it really depends on the design of the game.

Here's a video I found comparing load times with GW2(I couldn't find one with FFXIV):
https://www.youtube.com/watch?v=R23LH6uf_eA