Take a careful look at this one too. This is a big LED that should give you 6 hours. Around $100

http://www.performancebike.com/shop/...lisearch=true#

I have not seen one in person, so were back to the "How Powerful?" question again. However, for me Performance has had a good return policy. But some places don't take returns on electrical things. It might be worth a phone call. The Cygolight web site has some beam comparison shots and more details.