Going on Max lux from light-reviews.com it looks like its the Conqueror M-C1, it's certainly kicking out more than the C2 but I don't think the quad emitter is listed which is almost definitely is the brightest on DX...if not as bright as it probably should be.
I recently received my Romisen 4-Cree. It's nice and bright. Not perfect, it flickers on low, but on high it's BRIGHT. Lots of potential for increasing the output even more.