200-240 lumens is the range for maximum output of the U-Bin Seoul LED, at maximum current, assuming unrealistically good heat sinking, as rated by Seoul. That's gross output and assumes no optical losses either, which in genreal are about 20-25% for an LED flashlgiht, 30-35% for incandescent (for reflector-based lights).
I'd say it's realistically putting out maybe 180 lumens from the emitter (since the emitter isn't in a cozy fan-cooled test rig), and with optical losses, around 145 out the front,
initially. I believe that's where Kai tested the output -- but that's only initially, since it's direct drive it will quickly drop to more like 90-100 lumen output. Kai also tested runtime to 50% at 35 minutes.
I would stay away from this light -- just a direct drive with a big resistor that ends up wastign about half of the power. Switching the 5 ohm to a 1 ohm resistor and using a 17670 instead should double the battery life, but give the same irritating discharge curve.
Here are some lights that are much better in just about every respect (battery life, regulation, build quality, tint, and price):
Ultrafire C2 (HA-III version from Kai) -- I should be receiving this exact one pretty soon, it shipped last week. I have the original (black finish) and that was better build quality, and fairly well regulated if run on 2 cells. Biggest weakenss was the finish would scratch easily, which shouldn't be improved in the one I linked. Very good light for the mone, not as bright as the MTE to start, but better tint, more useful beam (IMO). $26
U2 Style This is another Cree flashlight sold by DX that a lot of people have liked. I never bought one myself but it apparently uses a boost driver, so it runs on 1x18650 only, and is very bright. Deep reflector should also be good for throw. $24.50
Semilar (from Kai) This is a small light (Fenix P1 sized) that has similar characteristics to the MTE light you're looking at. Brightness, and runtime should be similar, but this one is about 1/4th the size. People have liked this one as well as a cheap, ultra bright pocket light.