I really like having these energy saving bulbs and try to use them whenever possible. I say whenever possible because the types of light switches ( X-10 ) I have do not always support fluorescent bulbs. If I try to replace multiple light bulbs in a fixture with fluorescents, I get a weird buzzing noise. Or the light will not turn off all the way. I can get away with replacing 50% of the light bulbs with fluorescents. I like the idea of using less energy but I do not want to replace all of my X-10 switches for newer models just yet.