When watching a replay there should be the ability to show range indicators for champion spells and auto-attacks. An option for potential placement is inside the character window that pops up when you click on the champion. This can be useful for several reasons. First, Enemies Threat Range, with the range indicators you would be able to accurately determine the threat range of champions within team fights and the laning phase. Through the use of the replay going back to review how much closer could you have got or how much farther you needed to stand back. Second, it helps players understand the champion they are playing, understanding where you should position is a skill that could benefit to replay of situations with ranges of you and other players.
Thanks for your time.