Just follow twitter or reddit, and go by the time stamps to judge rather than the time zones. Usually they say 2 hours remaining, so judge by the stampage. Seems like going through a lot of extra loops just to play the game. I don't see the point in the disc since you won't need it to play the game. Unless you plan to pull it out and stare at it every now and then. And installing Steam on a different OS, just seems like another pointless loop, do you have a different OS for every program?