Actually, most big law firms do not use the built in track changes function in Word, they use more specialized (and in my experience, better performing) softwar

Actually, most big law firms do not use the built in track changes function in Word, they use more specialized (and in my experience, better performing) software that take a "before" and "after" Word file and then generate a nice "redlined" version showing insertions, deletions, moves, etc. in different colors. Examples include Workshare DeltaView and Litera Change Pro.