Frame rates would stay the same.
Gameing experiance would improve, because lag spikes would be smaller or non exsisting, atleast due to loading textures ect (that where the HDDs fault).
Does it matter? Depends on if you enjoy competitive multiplayer games, that happend to have lots of big (size) textures to load (mostly FPS games, like Crysis 3, or Battlefield 3 ect).
If nothing else, load times would improve. 
Getting faster into the game, or load a level ect.