From what I've read on CPF the true output of that light is in the 350-400 lumen range. That being said, it's a damn bright light for the money. Now only if runtime was longer.....
BTW, one of the Chinese makers is deigning a P7 long runtime bike specific light. Info here:
http://www.cpfmarketplace.com/mp/sho...d.php?t=176719