Pros: low heat, energy savings, instant on, lon life
These bulbs are ok, but not perfected yet. The "warm" version emits a very pleasant light.
I purchased one about a year ago and it works as-advertized except for one area.
The product description states:
"the GeoBulb has no mercury, turns on instantly, creates no humming sound, and can be used in colder temperatures"
The part about the huming sound is a bold-faced lie. The geo-bulb II emits a humming sound audible about 8 feet from the bulb. I contacted C.Crane after purchasing and they said some sound was normal but sent me a replacement in case mine was defective. The replacement bulb made just as much sound as the first one.
The sound is not terribly loud, but forget about using it in a reading lamp. If you plan to use it in a ceiling height fixture and have high ceilings, you probably won't notice it. Mine works great as a front porch light, which I don't mind leaving on due to the energy savings.