This is the problem with cheap generic LED lights from China, they rate them at 1200 lumens or some such extremely overrated number, which by the way Magic Shine does as well, and the light is actually closer to 120 lumens, the Magic Shine isn't quite that bad they're about 50% off. However, for $35 or so their not bad. And this doesn't even take into consideration reliability issues found in these cheap lights.
I also agree with SIXTY FIVER, for road use I think some people are going way overboard on lights; you're not going to come in for a landing on a runway at night, so to have 2500 lumens is just plain nuts. I think the sweet spot in road lighting is right around 750 lumens max. I have a Philips Saferide that on comparisons it appears as bright as most 1000 lumen lights, I rarely put it on high, I run it mostly on the medium setting which is about half as bright as high and I'm an older man of 60 with dimmer vision than most young people, and at half brightness I have no problems seeing far enough ahead riding at 21 mph or faster to make a sudden stop or to avoid something. By the way, the same is true with my Cygolite MityCross 480, I rarely run it on high either, usually the medium setting. That's why I think right around 700 to 800 lumens is the sweet spot for max output and about 450 for most riding purposes. OF COURSE THIS IS JUST MY OPINION.