I am noticing some issues but I am not sure if it is my Playstation 3 (40gb fat model) or just how the game is. I have noticed the framerate jumps a bit when I go from gameplay into watching one of those videos in-game and also when I played multiplayer something kept popping up, not sure what is was but I think it mentioned the hard drive maybe?
 
Thanks.

If it's mentioning the hard drive it might be that you should clear up some space, it downloads and saves stuff all the time when you play online.

I haven't noticed these problems, but I also haven't played much.

@NekuSakuraba:
I mean your HDD might be nearing maximum capacity. Delete some old game data or something (not save files).