Oh yes, the item is well heatsinked - the colour is noticable immediately at all drive levels, and does not alter with time (if the heatsink was not effective, the LED would take a number of seconds to go blue). The mounted part only dropped 2% of light output after being driven at 917mA for 2 mins 47 seconds - for reference, the P1D changes the same 2% on high in only 1 min and 5 seconds.
I checked the colour co-ordintes xy is .3086, .3127 - they put it firmly in the WC bin. Running at 220mA made negligable difference. The actual lumens seem to be correct though, assuming that the P1D runs at 700mA on high and is a P4 bin at about 84Lm at 350mA.
I thought that CREEs could only be bought in set combination of colour temp bins according to their order codes - is this true??
Cheers,
MJR