We got hooked up with some Exposure Lights to demo for 24 Hours of Moab. (Thanks to Kevin Day!) Each person on the team ended up running one as our main source of light. These lights were awesome. I had the opportunity to try the MaXx-D Mk.4. I mounted it to my handle bars and it lit my way for each of my three night laps.
Exposure lights are light and compact. No wires stringing to batteries. So I did not have to struggle to find someplace on my small frame and minimal stem to mount a battery. That was so convenient.
I ran a secondary light (I think) on my helmet. But I could only tell it was on when I turned my head. The Maxx D drowned it out otherwise.
They do have longer charge times than my other lights. Because my lap times were a bit longer, I ran a piggy back battery that easily strapped to the light itself. I did not have any issues running out of battery, neither did Matt, Josh or Chris. If you are looking for new or a first set of light, be sure to give Exposure a long, hard look. They are pretty sweet.