i agree, many of us do not have a DVD or no DVD player, or its broken
but as for large mem usage, so big is the difference not even
i have no problems and i have 2 gig ram, not even if i have bitorent or emule running in the background
thats a little stupid to say, any computer has dvd's or sometimes they just temporaly dont have it installed or they just download that game from internet, if thats what you're trying to say. And emule or another bitorrent client dont even take a GREAT ammount of ram. Timeshift isn't such a great game either, if you really want to make your pc feel like hell just try the new demo of CRYSIS
ANd yes i'm using a no-dvd version cuz its annoying to keep changing the dvd.