Detail Texturing is a very powerful tool that can improve the appearance of Materials by supplementing the base textures with highly repeated detail textures.  Keep in mind that Detail Texturing can only help to hide pixilation to a certain point, and allowing the player's camera to zoom into objects to an unreasonable degree can negate the benefits of detail texturing.  Also remember that adding detail texturing could add two or more additional texture lookups to your Material, which may present performance or memory issues, especially on mobile platforms.