Overall the material and construction feels good. It is comfortable to wear and feels secure once on, plus my phone feels safe. However there are a few points to consider
Point 1. Like many others have said, this is OK as long as you dont have normal size mans arms. Considering that you are probably buying this for running or training then you will at least have some definition in your arms. In that case you may find that the velcro straps aren't long enough. My arms aren't big by any stretch of the imagination, but I do struggle to fasten this.
Point 2. While the description says that it is useful for smartphones, it depends on your phone. I have a HTC Sensation and althouh the phone feels safe and snug, and the clear screen still allows the touch screen to work, there is a problem. The material at the bottom doesnt allow you to access your action buttons, so trying to wake up your screen, or pull the "ringlock" is almost impossible. Its definitely designed for people with iPhones.
4 and a half stars for quality, minus 1 and a half stars for functionality and useability