Look at it this way: you can choose to design a head lamp with a HID projector for the main lighting element and either use a power-hungry, heavy, heat-emitting halogen which will only be able to be configured spatially inside the lamp, or use a number of small, efficient LEDs to perform the same role while offering more flexibility as far as design and placement. Guess which designers and enginners tend to choose these days?
I don't think you'll see LED's being used anytime soon as a high beam source except in uber high end vehicles, and then with rear facing LED's that reflect off the back of the reflectors or some techno shield covering the LED. LED's are just too offensive and irratating when used uncovered if they actually have enough lumens to light up the road.
I was wrong about a winning Baja Truck not using LEDs.....the Monster Energy Trophy truck was sponsored by Rigid Industries who make very nice aftermarket LED lights. The truck had 304 individual LED's in multiple light bars, pods, etc. Total cost of these LED's is approximately $6500.00. You will be shocked when you add up all the amps needed to run a system like this (about 75 amps). I'm guessing you could run 10 HID off road lights at 30 amps and have double the lumens. And trust me, those are not off the shelf LED's you and I buy at the local truck accessory outlet. Baja race trucks are so punishing, that nearly all units are custom made. Back in the late 1990's when Ivan Stewart was winning all the Baja races, Hella was the lighting sponsor. The Toyota team contacted my company wanting us to build them some sort of a clear cover to protect the lens from breakage on the then new HID Hella 4000 lights (about $1600.00 a pair then). In talking with the team and about the lights, it came out that the off the shelf lights would fall apart very quickly during the races and every light was custom made with additional support, etc to keep them intact.
I'm not adverse to LED "lighting" if it is superior to halogens, HID's etc. What I do not agree with is the stupid strips of LED's that detract from the lines of the car and don't put out usable light. As I said at the start, I would never disagree with someone that likes them, but "lighting" and "style" are two different things in my mind. That boomerang LED shaped crap in the lower bucket of the new C7 looks so out of place, I just can't imagine what there were trying to achieve with that look.
When it comes to lighting, correctly designed reflectors, etc are much more important than the lighting source. My wifes 2008 Sequoia had fantastic lighting from halogens. Her 2011 Mercedes ML has great lighting from HID's. We rented a Ford Explorer last week while on vacation and it's projector style lights ****....I mean bad. We also rented a Maserati Gran Turismo and it had good lighting....but not as good as the Mercedes. I'm sure as technology progresses, LED's will get better and better. But at what level is the watts per lumen and cost per lumen going to outweigh the advantages when we use the word LED's when referring to actual lighting for seeing down the road? As far as I can tell, it's hard to beat HID's for both watts per lumen and cost per lumen.
Cheers,
George