This weekend we just replaced 50 of our 400 watt metal halide pole lights with the Olympia CL-100W11H-55K-E39 corn cobb style LED lamps .We had replaced 8 of these about four months ago and are very happy with the light output . Plan on doing the other half of our parking lot next . We originally had thought about replacing the whole fixture with LED type fixtures but decided to got with LED corn cobb style bulbs due to the cost . The lamp is rated 50,000 hrs and has a 5 year warranty . Has anyone done any similar and how long did they last ?