A friend of mie bought the Nightstar CS flashlight which is very similar to the one in the add. His is very well built and seems pretty tough. It works pretty well, but the light is not too bright. What can you really expect from a single LED light though?
In complete darkness it is fine to light your way or rummage around in your tent or home for things.
I kind of look at it as the opposite of my Surefire, which is super bright, but burns through the batteries.
After trying one out I am thinking od purchasing one.