I used an armband for awhile, hated it. Have used a Flipbelt for about a year and love it. It's worth a look unless your dead set on the armband.

I had a Fitletic armband before, was awesome but sadly was too small to accommodate new larger phone. Switched to Armpocket who at the time where the only ones to make very large armbands. It blows. Zippers are of much lower quality, they rust and broke due to sweat, and the material absorbs odors, whereas the Fitletic did not.

You know the 6 and 6s are the same size right?