I did an an illumination comparison between the 2 LED high power 31mm festoon bulb and the 1 watt Luxeon LED module tonight. The 2 LED module put out about 90 lux and the 1 watt Luxeon did about 180 lux, both measured about 6" from the LED.

The Luxeon unit seems to throw light a lot farther and it has a 180 degree pattern and is bright enough that it leaves spots in your eye if you look directly at it up close. The 2 LED unit has a slightly narrower beam with a 120 degree light pattern. I guess for the price, the 2 LED unit (~$7) gives you more light for the money than the Luxeon unit (~$30), but the Luxeon puts out more light overall.

Nice thing with either unit is you could leave them running full time and not drain your battery. I was talking to George (from TaskLED) and he has the Luxeons in his FJ-80, both up front and in the cargo area. One time he was on a business trip for about a week and returned to his FJ in the airport parking lot only to find he had mistakingly left the cargo LED on when he had left for the trip. The LED was still going strong when he got back and the engine fired right up with no problems.