Both are neutral, I also have the 21700 body for the 18650 (If Gene made a 2x21700 I would be all over it) it actually gets pretty close to the runtime of the 2x18650.
I have the Super Hound Dog and the 18650 Wildcat (running without the diffuser) up close you would be hard pressed to tell the difference in output. Of course the optics on the SHD throw better at a distance. I think the only place you’ll notice where you take a hit going with the 18650 is runtime.
It was the Surefire M4 Millennium with an LED upgrade for a long time, however, I just purchased a Malkoff Super Hound Dog, which is essentially the evolution of the M4.
SOLD!
B.O.S.S. 70
XP-L 4200K LED Primaries
Red 640nm Secondary
I have been too afraid to use this since I got it... haha, I guess I'm not cut out for the high-end flashlight market. It can be yours for $560 shipped Paypal, CONUS USPS.