I've had mixed experiences with the CFLs. I bought four 10 packs at Costco nearly four years ago and over half are still burning. Most of the rest died within a couple of months of purchase, but some started blinking out after a couple of years. One died last night.
I bought some Westinghouse Daylight CFLs at Target last year, and even though I like the color spectrum better, and even though they have the same lumen rating, they're noticeably dimmer than the standard spectrum bulbs from Costco.
I picked up two 3-packs of LED candelabra bulbs at Costco about 2 years ago for the exterior lights on the garage. CFLs just didn't last in that application, (on a photocell) so, since these came with the Costco warranty, I decided to try them. IIRC, they were about $15/3 and use 3 watts. Not very bright, (supposed to be 15 watt equivalent) but they serve the purpose I wanted. So far, no problems with them. I DID find out they don't like to be dimmed...One of my exterior fixtures on the side of the garage had a built-in dimmer/photocell/motion sensor. At dusk, the light came on at half-wattage, then, if someone triggered the motion sensor, it came on at full wattage.
I tried one of the LED bulbs in there...I could see it physically smoking...so I quickly removed it. (It still works fine, but there's a black smear on the inside of the bulb housing) I removed the dimmer/photocell/motion sensor mechanism and replaced it with a standard button photocell and the bulb works just fine.