One of the authors of the RUSA Handbook mentioned a few times the usefulness of a hybrid headlamp for supplemental lighting and mentioned the Petzl Duo. I can certainly see the advantage of a hybrid (a superbright LED, halogen, or xenon bright light that shoots 100 meters, combined with a regular LED lamp for closeup light for seeing cue sheet or bike computer). I checked at our local outfitter store, and models include the Petzl Myo 3, Petzl Myo XP, Black Diamond Icon, and the Princeton Tec Apex, just to name a few. There are several more, each with different characteristics of brightness, battery life, weight, on/off switch, etc.
Since commuting and touring would use the lights in a different way, my question is for any long distance cyclist who has actually used a hybrid headlamp in your randonneuring. How do you evaluate the various characteristics of hybrid headlamps for long distance purposes? (e.g., Are a couple of extra ounces of weight worth the extra battery power? Do you use the high beam 1 hour per night, or 4 hours per night? Is the extra light of a halogen high beam worth the disadvantages of a halogen bulb, etc.) Any help from the veterans would be appreciated. Thanks.