Hi Gang, Just came back from LightFair where I attended all the LED workshops and seminars and got the low-down from researchers and manufacturers. Here's a few points that might interest you. 1. LED research has progressed very rapidly and LED manufacturers have suceeded in creating highly efficient, very bright and long-lasting LED's. From an efficiency stand-point they are now equivalent to compact flourescents. In brightness, they are making LED arrays comparable to 35w MR-16's. Lamp-life is expected to approach 100,000 hrs. But. . . 2. Heat. Heat is the number one problem with LED's. One early LED fixture from a major manufacturer has already been pulled from the market because of failures. It takes some pretty sophisticated engineering and a lot of metal to conduct heat away from LED components. Many fixtures on the market today will have lamp lives in the range of 10,000 to 20,000 hrs. instead of their promised 100,000 hrs because they fail to dissipate heat sufficiently. Contractors and Architects purchasing LED fixtures today have no guarentee that the fixtures will perform anywhere near the specifications. 3. Color. LED manufacturers have succeeded in developing a fairly good white light from LED's. They do this by starting with a blue LED chip and coating it with a phosphor. Unfortunately, the phosphor coating tends to be inconsistant resulting in slightly different colors from chip to chip. Also, the blue LED varies in color from batch to batch. To address these variables, manufactures measure the LED colors and put matching chips into certain bins. When they sell a bunch of LED's, they try to take them all out of the same bin so the colors will be fairly close. But when you as a contractor go to buy say, 20 LED fixtures, the lamps may have come from different bins and the resulting light may be noticably different from fixture to fixture. One designer showed us photos of projects where LED's where used as wall washes; the beam colors varied haphazardly and the result was awful. As the technology develops, these color inconsitencies will become less, but researchers seem to be years away from that time. 4. Throw-away's. You may not have noticed, but lighting manufacturers selling LED fixtures do not also sell replacement LED's for those fixtures. Why? Because the LED's are supposed to last over 10 years. Why does this bother me? First, no one really knows how long the LED will last. (Note: LED's are only tested for 6,000 hrs. The lumen deprication curve is then extrapolated to 70% to estimate the life.) LED's can also break and need replacement. LED's are also getting better; maybe you'll want to swap out this years LED's for the next years. Also, remember that LED's don't burn out, they get dimmer. How many homeowners will want to discard their expensive fixtures just because they're a little dimmer? More likely, the homeowner will gradually get more and more dissatisfied with the lighting design; she will live with the diminished lighting for a long time. It would bug me as a designer to think that many of my designs will gradually degrade instead of maintaining the same level of brightness. In conclusion, one of the researchers put it this way to the group of manufacturers and designers in the room (I'm paraphrasing). "You are the early adopters and I commend you for that. Understand, however, that you will not get the results you expect. It will take 5 to 10 years for LED's to become standardized to the point where they can be specified for lighting with confidence." My advice to contractors at this point is to be very very wary of these new LED fixtures. I would certainly never use them in a big or important project.