I just went to Costco, and they have some LED retrofits similar to those Cree ones at Home Depot. They are made by a company called Luminus, and the model is C-UPR63M. Google doesn't turn up much:
https://www.google.com/search?q=c-upr63m&oq=c-upr63m&aqs=chrome.0.57.3231&sugexp=chrome,mod=17&sourceid=chrome&ie=UTF-8
However, the box says 3000K, 1200 lumens, 18 Watts... and it's only $24.97. So I picked one up to test.
I measured the lux output on my countertop in the kitchen below the light and on the floor radiating out from the light.
Cree: 121 lux on the counter directly under the light, roughly 68-75 lux out to about 4 feet on the floor
Luminus: 238 lux on the counter directly under the light, roughly 112-121 lux out to about 4 feet on the floor
I'm pretty impressed by these. Before I even measured the lux output, it was obviously about twice as bright. The color is great, and the spread of the light is much greater as the Luminus illuminates the top of my cabinets, something that the Cree doesn't do. A side effect of this is that there is definitely more glare from the lights, even when you're on the other side of the room. The color is 3000K, and is a bit crisper than the Cree, but not too much so. I actually prefer the color of the light. No CRI is listed on the box though, I assume it's somewhere between 80-85 like most other LED's, the Cree is 92 which is very high. I'm terribly colorblind, but I can still tell how well things render color. Pinks and reds looked more saturated under the Cree. I wouldn't say they were washed out under the Luminus, but they were definitely more muted. The light doesn't have the weird greenish hue that some of the LED's I've tested have put out.
One of the nice things about the Cree is the light sensor and multiple colors of LEDs in it. This allows the light to constantly adjust the color of the lamp to put out a specific temperature color as it ages, or between different bins of LEDs. I doubt the Luminus has this, but I was too anxious to get it in and didn't take it apart.
Ooo! Another thing, it works with my Z-wave dimmers... by itself. I unscrewed an incandescent on a dimmer and screwed the base/adapter thing for the LED into it. It dims, without other incandescents on the circuit. It appears to dim down to about 25%, but I didn't spend a ton of time with it or measure the light output.
I'll use it for a couple of days, and if I have no complaints, I'm probably going to pick up several more of them.
