I've purchased a bunch of Ultrafire and similar chinese made stuff.
Fit/finish is nowhere near that of Streamlight and the like....
Small stuff like burrs on the threads of the cap are normal.
BUT...
Once you get past that, you're golden.
I've dropped a bunch of mine in pools, mud, etc. Banged them around, ran one over (forgot I left it on my bumper......whoops!), and have functioned flawlessly, except ONE, my oldest one. The driver failed, but 2 imns later I soldered the LED directly to the battery contacts, and it's still working today, years later...
There is a REASON that flashlights cost $200, just like there's a reason that YHM rails are ~$100 while Troy and DD are $200+
You DO get what you pay for, and you will get the best by paying top dollar for known brands, HOWEVER, you just can't beat a 300+ Lumen flashlight for $25..... At that point, they're almost disposable, but I've yet to find them to be. I only buy new ones to get more light and longer battery run time from the same (or smaller) package.