@JB: It's Worse Than That
Recently bought Fallout 4 for the PC. Put the DVD in the PC and it buzzed along loading the game. Then it came up with a message to say that the game was installed but it would need to load additional data before it was ready to play. A quick trip to the Steam Download Manager showed that it had installed 5Gbyte so far and was downloading 21Gbyte of 'additional data'!!
Worth the wait though.