I got fed up with GPS issues, both phone and wrist-top (both are sucky in the woods and amongst tall buildings). Thus, I went to a Garmin FR70 with foot pod. I find it much more consistent and reliable for my data geek needs.
...of course, if you're running barefoot it may not be the most effective solution.
...of course, if you're running barefoot it may not be the most effective solution.