Ok, I've had the Emitter for a few weeks and everything I quoted above is true, but I don't know how NiteHawk can claim the Emitter to be as powerful as a 10w halogen. I had a NiteHawk Viper II, which is 5w halogen and I don't find the Emitter to be as powerful as that one. It's very close though. Actually, I find the Emitter beam more "useful". The halogen beam, while it projected more light, was more like a small "sploch" (is that a word?) with no scattered light. The Emitter beam is a bright circle (in practice, it's an oval since the light is projected at an angle), surrounded by a larger and dimmer circle, and then some scattered light. I can project it further and still see what's closer to my front wheel. While I returned the 5w halogen, I decided to keep the Emitter.

More about the Emitter:

-I find the 10% option is very useful to conserve energy when there are plenty of street lights. It can act as a be-seen light.
-The orientable head is great! Something lacking on most lights. There's no room on my handlebar and there's a bag in the way. I mounted the Emitter on the stem (sideways). With other lights, this means the light would point at the sky, with the Emitter, I just rotate the head to aim at the pavement, under the handlebar bag.
-The on/off button is annoyingly difficult to push. A problem if you switch often between high and low beam. And the sequence is high/off/low/off. It could use a sliding switch instead, with the off position in the middle and high/low on each side, for example.
-The mount is solid. I don't have any jiggling problem as others have reported. My concern is durability. The quick-release attaches to the base of the battery pack and the rest of the light (top of battery pack and head) is secured only by three small plastic parts that snaps the battery pack shut. It's solid but you have to unsnap and snap every time you change the batteries. I'd be afraid of breaking one of these snaps after time (Hope it's clear, my English falls short here). Also, it's easy to think the battery pack is snap shut while it's only holding by two of the three snaps. Vibrations could make the light fall off then.

There's a user review floating on the web that compares the Cateye EL-300, the NiteHawk Emitter and the Planet Bike Super Spot. Click here to see it. I'm curious about the Super Spot, since it sells for 26$ CAD at MEC, batteries included! That's less than half of what I paid for the Emitter (65$ CAD at MEC).

Edit: There's another review, but it seems the poster only changed the name of the EL-300 for EL-500. Something doesn't look right. Anyway, it's here.