I just got a Lumotec Cyo, and it provides all the light I need for riding in absolute dark while being 100% comfortable (and I'm very very picky about having enough light), and enough light for riding like 80% comfortable in rain or in sparse city lighting (where you need more light because your night vision is affected by the ambient light). Someone less picky would probably say it was good enough for anything. I really love the shape of the beam - it puts light right where I need it.

If I wanted more light, I'd add a helmet light so I could point it to see around corners.