I want to start using Steam. I have heard that if you buy a physical copy of a game that uses Steam, you still have to download the game, and that can take a long time. Is that true?
If you buy a physical copy of a Steam game, you have the activation code that will be bound to your steam account, and you can use the provided DVD to install the game (into Steam), but steam will afterwards download the additional materials/updates/DLCs/etc.
So depending on your internet connection, having a physical copy is a good thing since it can save some time.