I had the previous model, the S9. I really liked the functionality they provided. Not having any cords was a wonderful experience. Like you, I've also had problems while running on the treadmill, when I don't want (or have) my armband. The two down sides (and maybe this has been remedied with the S10): 1. I sweat an ungodly amount when I'm running and the sweat seemed to want to get in my earbuds on this model after about 15-20 minutes of running. 2. Battery Life. The battery life of my S9 is nearly non existent now. It lasted me for about 1 - 1.5 years before the battery wouldn't last for an entire workout. Again, the S10 may be better than the S9 in those respects, but when I get the disposable income again, I will probably be purchasing the S10, or its replacement.