There's not much to say besides they're cheap (as you know) and they fit my big head snugly and do not move when I shake my head. I can even head-bang with these while I "up the irons".  I plan on running trails and such with these and they will be great.  The construction is solid from what I can tell with my hour of wearing them.  I'm not expecting these to last forever, nor should you.  The only thing I can't really touch upon much is the UV factor.  They block out sunlight, but what spectrum I do not know.  I researched a little about Polycarbonate but that seems to be more about the strength itself.  It states "full UV400" so I guess I'll trust their word on that one.  If anyone cares, I got the black/orange combo.