I ran some tests and thought this might be useful to someone.
CREE 50w DIMMABLE LED PAR 20
TPAR20-0553040FH25-12DE26-2-11
40º Flood
Bright White 3000ºk
Build Quality = Excellent
Customer Support= Superb
REVIEW:
Product was supplied by CREE for testing and evaluation with Insteon forward-phase triac dimmers.
Be aware that SmartLabs is likely to change their product design and components with each firmware and revision. These test results were on the noted products only.
The lamp performed better than expected on the 2477D with regards to consistent dimming values in the upper range 7%-100%.
(see LUX values in charts)
There is no dimming in the 1%-6% range.
* The LUX chart value at 0% is from the ambient room light, not the LED lamp. The lamps do turn off at 0%.
One negative is a flicker from 11%-17%, which makes it unusable in this range.
One benefit over halogen is that this LED holds its color temperature throughout the dim range, whereas halogens get warmer (ºk) as they dim down.
The 2472D and 2457D2 tested did not experience any flicker throughout the range, and their LUX dimming values were almost identical with each other.
There is no dimming in the 1%-6% range.
* The LUX chart value at 0% is from the ambient room light, not the LED lamp. The lamps do turn off at 0%.