One thing to consider is optics. If your commuting light is mainly for 'being seen' in traffic, then my personal preference is to avoid a shaped beam like the Edelux. My Edelux produces a nice beam that is, by European standards, courteous to oncoming traffic, other cyclists, pedestrians, etc., but in my opinion, it doesn't put the light out where it's needed most on the mean streets of North America: in the faces of drivers (obviously not appropriate on trails or unlit roads).
Very well said. I like my Cyo N for unlit highways, but for commuting in city traffic, I routinely supplement it with a battery-powered light that sprays light all over the place, because the cutoff-equipped dyno lights just don't look very bright from above the cutoff. It's too easy to be overlooked amidst the other traffic.
Another problem to take into account: when you stop, the light goes on its standlight and runs even dimmer. That's not good when you're in the middle of a hectic 4-lane arterial intersection, waiting to make a left turn. My Supernova had an exceptionally feeble standlight, the Cyo is better, but this is another area where battery lights can save your bacon.