Upgrading from incandescent landscape lights to LED is becoming very popular. Some lights bulbs such as the 921 used in path lights last only 3000 hours if your lucky. Often they last as little as 1000 hours. The LED retrofit bulb for the 921 is the T-5 Wedge by Kichler and it is wet rated which is important for lighting fixtures that do not have enclosed bulbs. The T-5 LED is rated for 30,000 hours which in most application will last well over ten years. You are also looking at a power draw that will be 90% less. If you want to save on your power bill and be more environmentally friendly the LED upgrade may be for you. If you tire of constantly have to replace incandescent bulbs that go out every month or two on an older system the LED upgrade can make replacing bulbs a thing of the past.