This is definitely true for the vast majority of LED bike lights. These are the kind that run on a couple AAA batteries and contain a cluster of LEDs. The Luxeon 3 and 5 watt bulbs the Dinotte uses are much better for seeing by. They put out around 80-120 lumens and can drop four 2600mAH batteries in about an hour and a half. They've got a very bright, but narrow beam pattern. A friend of mine likes his Blackburn System X6 quite a lot. It comes with two light pods- one with a narrow beam pattern, one with a wide one.

Don't get me wrong--HIDs will still beat the pants off of the best LED. For me though, LED is a great balance of weight, light output, price and power efficiency.