I wouldn't say bones are 'better' than empties. Bones/Armatures are great for self-contained rigs like characters but often mechanical systems don't require that. Chris Kuhn builds some amazing mechanical rigs outside of the bone/armature system: https://cgcookie.com/course/rigging-train-wheels-within-blender/
I agree Kent, Chris is a very talented artist and I understand why you have him posted on cgcookie.com. I guess I am still too much a noob to understand why he wouldn't use a bone rig. I was under the impression bone rigs made the dopesheet more organized and a bunch of other reasons. Thank you for your response!