The only warm tint LED I have is a Malkoff M60W in a surefire host, like others have said its not like a incan but it is much better than a cooler tint LED. When compared to a cool tint LED the advantages of the warm tint seem to be increased depth up close and at a distance, color rendition that's near true, no fading of tint as the batteries run low (more incan related), and also at distance you don't get the graying out effect.
I think its a better option than a P90 in my C2 but beyond that I'm not sure, 3 warm MC-E's in a maglite could be interesting though
If I'm not mistaken, the M60W is neutral white and not warm white. I've tested cool, neutral and incan side by side.
On trees, cool white washes out the colors. Neutral white's colors are also washed out. There is almost no depth perception with these. Their CRI also appear to be similar (CREE specs them both as 75). Incan looks way better and the depth is now there. The tree suddenly came alive.
On a box which happen to be red. Again, cool and neutral appears to be same. Dull boring colors compared to incan which suddenly made the box look very 3D and the colors jump out.
So, my own conclusion is...
Cool white = Most efficient, very bright and glaring. Good for blinding people and when you need a lot of light for a long time.
Neutral white = Efficient and bright. Very soothing tint to the eyes. Makes eyes less pain when I use it. Good EDC tint.
Incan = best color rendition and really good for visual perception. Very inefficient.
Now I need to try some high CRI LEDs. Anyone wanna make some for less than the asking prices of a custom? =D