Nono what they mean is this, ps3 owners have to install the game to their harddrive it isnt optional, but with the 360 you can chose whether to or not, hard drive = little better performance, but you dont have to...
Where did you hear this? Why would PS3 owners have to install GTA IV on their PS3's hard drive? Especially considering how much space is on a Blu-Ray disk.
so that all the videos are preloaded on your hard drive equaling barly any loading time at all....which was said about gta 4 ages ago....its also the same with Devil may cry 4