I use a Crucial M4 500GB disk...it's a couple years old, but it works good. I routinely zone in before other people in the PT (skipping cutscenes, etc.)

However, I also put a Samsung EVO 840 SSD in my PS4 (also 500GB), and the load times on the PS4 are noticeably shorter than they are on the PC.

So take that for what it's worth. To me, that says that Windows is continuing to hog resources even though the game is supposed to be in exclusive (full screen) mode.

What OS are you using? I've noticed the game runs better on Windows 8.1 than it did on Windows 7 or even Windows 8.0.