Some of those Chinese lights are a decent deal. They are nowhere near the quality of some of the more expensive lights, but they are high enough quality to be perfectly serviceable. And they are dirt cheap.
But you have to remember that these lights are advertised using "Chinese specs". So when they say "7 watts", they really mean "1.5 watts". Similarly, "400 lumens" equates to "115 lumens". You should also expect the hardware to wear out farily rapidly. Switches, stuff like that, on these Chineses lights do not last for long. Heat sinking of the high power LEDs is usually substandard, causing premature failure. Expect a year or two of service, that's about it.
But once you learn to ignore the ridiculous and outright impossible performance claims, and understand the limited lifetime of these Chinese lights, you often find that they are dandy little lights for the low price you have to pay for them. I have a couple myself and I was happy with them (until they died). I now have much higher quality 4Sevens lights and Olights, but these replacement lights cost quite a bit more than the inexpensive Chinese ones. For someone who is not a Flash-a-holic, I recommend the Chinese lights that get good ratings (not all of them do).