I picked up one of these lights last week from the LBS. I got a smoking deal, so I could not pass it up. So far I have been out for three night rides with one lasting for an hour. I ran the Ion700 on full 700 mode for the entire ride. I averaged 15mph with the outside temp at 91 and the light only slightly warmed and did not step down on output once it did get hot. Over all, I am very pleased and will possibly pick up another just to add to the illumination.