One of the major benefits of LED bulbs is that they can last for up to 50 000 hours. That said, it’s definitely worth buying good quality LED bulbs. Those LEDs that seem to be a real bargain, are usually made using cheap components, with the result that the driver circuit powering the LED is far more likely to fail earlier than it should do so.
If you were to change 10 of your old 50w incandescent downlighters to 5w LEDs, you will enjoy a power saving of 450w and, if they run for 5 hours per day, you will be able to save up to 2.250kwh per day.