The british competitive mountaineer and runner Simon James, has tested and reviewed the V3pro rechargeable: "Comfort: (5/5)
It's very comfortable to wear and also the overhead strap provides good stability and comfort, needed above 150g. A headtorch much heavier than 200g is just not very comfortable for trail running, and packing light for the mountains is key. The battery pack balances out the light at the front, and although slightly heavier than the Air version it's not too noticeable. Personally I'm not a fan of putting battery packs in pockets or elsewhere, I just get caught up with even more cables hanging off me so I tend to avoid these designs!"