Has anyone tried a workout using just the AW2 and then again with the iPhone to see if there is much difference in battery usage? I'm stuck indoors at the moment so haven't had a chance to use any workout apps. I'm intrigued to know the difference. My plan is to use just the AW2 when running, but I often go hiking too. The Hikes can be anywhere from 3-6 hours long, so I'm hoping the AW2 + iPhone will give me enough juice to do the whole distance with the watch. When it's raining with low visibility, the water resistant watch will be a godsend for getting a quick bearing.