If you are one of the many PlayStation 3 owners that are going to buy Mass Effect 2 either way your HDD will be considerably used up. Even if you aren’t going to download the entire game which takes up 12 GB, the install for a retail disk is apparently a massive 4.5 GB.
While not quite the same size as Gran Turismo 5, players will still have to wait a while when they finally get the game before it’s playable.