I have to give another vote to the Jaybirds. Ive had the X2's for 2 years and have ran in the rain, and high humidity soaked in sweat. I've never had an issue. It comes with a large assortment of fitting accessories. It took about 30 minutes for me to find the right combination that felt right. After that, they felt great and never moved. They stay put while running and through crossfit workouts. If these ever die on me, I'll be getting whatever version they have out at the time.