I own at least 20 China made front light and 4 of the MJ818 tail light. Of these 24 total lights, I had three failed on me. One had waterproofing issue which I prevented from being an issue. One light did not turn on after several hours of use. Another front light had a bad solder joint, while the last one was from the Magicshine 818 tearing a solder joint from turning the ring. I don't personally use all these light because I only ride so much, but I do lend them out to friends, coworker and neighbor who does use them and even some of them get abuse. So they pretty much did get some kind of runtime testing.

Three bad light out of 24 seem not to bad considering the cost I am paying for these light. However, I will admit that the MJ818 does have some flaws with their design with the housing and switch and they are prone to have wire tearing out after some use. Another thing to consider is that some of these light I got were still in their early development stage and some improvement was still in the making while other were given to me for review. Given that fact, I kind of expected a higher failure rate than what I have experience so far.