If you're lighting system utilizes energy saving motion detection; replacing incandescent and halogen flood lights with CFLs may lead to premature lamp failure. CFL's can take up to five minutes to warm-up and repeated on and off switching as well as short "use" time are the common cause of under-performance.
Because of the high cost of LEDs, check carefully before installing that the product is rated for outdoor use and or enclosed fixtures. LEDs have no problem with repeated turning on and off and performance actually improves in colder weather and they contain no mercury or lead. LED bonus; LEDs don't emit any UV spectra and therefore insects are not attracted!