I don't have LD15 to compare, but remember rejecting it at the store because of all these "tactical features" on it's surface and the twist action. Also, I have a doubt in Aluminum durability for such a thin walled case.

3000K one emits a reddish light very similar to powerful incandescent light bulb light or a day light. I have ordered the 4000K now. It should be more bluish, typical to LED lights. The 3000K must reveal more life like colors in the dark, compared to 4000K. But 4000K must be a bit more powerful revealing things in a distance.