All good features as described in the product description - waterproof (I have used it in HEAVY rain) - everything in my 'waterproof' backpack got soaked, but the phone was ok - a little moisture/condensation underneath the plexi-screen, but nothing too problematic. The phone fits well, I can use my external battery with it, headphone plug in properly etc etc...as I said - all good features.
The first and only issue was the rotational aspect. It's spring loaded, so you can only tighten it a certain amount and sadly it meant the case would rattle around if I was cycling anywhere but a velodrome. There is a fix - unscrew it completely, take out the spring, shave off some of the plastic with a sharp knife (careful) so that the case bracket sits more snug with the bracket attaching to bike. Then screw this fully on and voila. No more rattle, plus I'm not worried about vibrations as the case for the phone is sturdy and padded enough.
I have 'tested' the ruggedness of the case. Before applying my 'fix' one part of the spring mechanism snapped (my fault - I tightened it too much then applied too much force trying to turn the phone back around to the orientation I wanted, after it had rotated while I was cycling). The phone went flying in the case, hit the floor hard and is absolutely fine. So at the very least, the case works...!
I'm happy with it now I've made my modifications. It might work for you as is, but you can get rid of the shake rattle and roll without too much hassle.
3/5 purely because it didn't work the way I wanted it to out of the box.