I also carry both. Initially, I carried the bag as a back up in case I forgot or dropped my horns (both of which have been know to happen). It is difficult to get the initial "clash" of horns sound out of the rattle bag without bruising your hand. It is also difficult to get the volume out of the bag that you can with a P & Y set of antlers. That being said the bags are MUCH lighter and much easier to carry, especially if you have a good hike in front of you.

The best part about using a rattle bag is no bloody fingers from being smashed while rattling with a real pair of antlers!!