Hello, i just received my D4S SST-20 5000k, and globally i love it!
As other already said the beam is a bit greenish in the lower mod, nothing too dramatic in my opinion but i'm not a tint maniac ( no offense there
) i just like my lights around 5000k and i'm ok with 65/70 cri.
Inside, on a white wall i can noticed the greenish tint, but outside not really.
At higher output level the green is gone and the beam is whiter than my blf Q8, i like it.
I was a bit worry about the heat generation of the SST-20 5000k, on turbo the light get hot pretty quickly, that was expected, but i thought it would be way worst than that, see the video below.
Here is a crappy beam shot in lower mode, left to right : Emisar D4S SST-20 5000K > BLF Q8 XP-L HD 4750/5000K > Astrolux S1 XPL 3D 5000K > Convoy S2 XM-L 6500K

And a 3 min thermal test video with an ir thermometer and no cooling. the light was calibrated before the test at my ambient temp, 21° Celsius.
The ceiling temp was set at 60° Celsius.
i'll keep it set @60° ceiling for the moment, outside temps are around 2° Celsius so it's a nice hand warmer.
But during spring/summer a ceiling @50/55° should be more reasonable.
That's my first Emisar light, and now i do understand why peoples love their products so much.
Thanks to this thread i pushed the button for the D4S and i'm glad i did it. 
Only problem, now i want more Emisar flashlights. }D