Supcase Armband case for running/exercise

I picked up the Supcase armband case from Amazon since it has openings for all the features of the phone so you can still use it during a workout (Camera, audio jack, spen, fingerprint reader). The case material is a very thin flexible rubber but when put onto the phone actually feels pretty solid with a good fit. Due to how light this phone is, when attached to your arm it does not bounce around much at all though I thought it might initially. The strap loops through a slot in the back of the rubber case which could be a point of failure, but that doesn't seem to be much of an issue if the strap is tight enough since it really doesn't bounce around. Time will tell about the durability. I intend to mostly use it for biking so bouncing around is not as much of a concern than it would be for running (it really doesn't move much at all). I'll update after I give it a few rounds of use. Attached are pics.
http://amzn.com/B013D2GDTS