3 brand new Energizer Max batteries got me about 3 hours of burn time. It's a pretty bright light, bright enough to be used as a primary for recreational night dives. Focused bright white center with a large dimmer cone of light, so you get a bright spot with a nice flood that lights a pretty large area. Brighter than rental lights provided by several of the dive shops I've been diving with. Not as bright as the pistol grip rental lights that are usually 3-4" in diameter. Very solid to hold and seems rugged. Slight delay when you turn the light on in the water sometimes - thought it wasn't going to work one night, so I had someone on the boat hand me one of the rental lights and by the time they handed it to me, the Hollis turned on.
Anyway, seems pretty good and I'm happy with the price/performance raio, but if you're looking for something to turn night into day or appear like you're carrying a car headlight underwater, this is not the light.