I posted this in the Petzl Myo warning thread, but I've tried out the Petzl Ultra. It's pretty fantastic. Like no other headlamp I'd ever seen. I woudln't use it on trails for which my trusty Tikka Plus or Myo XP are adequate, but on gnarly descents the Ultra proves its worth and its certainly worth a few extra ounces. I can't say if it's worththe extra money. I've got a short review in the following post: http://blog.irunfar.com/2008/08/orsm-08-in-brief.html .