When attached to optics, honeycomb filters reduce clarity, contrast, and brightness. This not only makes targets harder to detect but reduces your ability to observe impacts, trace, splash, etc., especially in low-light conditions. Since you are reducing your optical quality and target acquisition capability, only use them when you need to. I know it’s the latest “fieldcraft bro” trend, but finding and hitting your target fast is usually more critical.
The honeycomb has to be a precise depth and constriction in relation to the lens size/geometry for it to truly work 100% with magnified optics anyway. (It’s way thicker than most people think.)If you look at how deep and tight the mil-issued Tenebraex filters are compared to some of the aftermarket printed ones, you will see what I mean.
Even when doing sniper stuff overseas, I generally used them when I had to be sneaky and the sun was forward of my position.(I believe true sniper field craft is becoming a lost art at this point, but proper mission planning used to include making map overlays that showed where the sun would rise and set with respect to your potential hidesites.)
I would never use ARDs in a competition, but I will make sure I have the tubular sunshade (that most guys leave in the factory box) on hand or installed. Sunlight at certain angles can white out your image and create visual artifacts.
Due to the lens angle, curvature, and coatings used, some MRDS have terrible forward signatures. Many manufacturers use lens treatments on red dots as a way to need less power for dot projection and therefore longer battery life.(I love the Trijicon RMR for rifle use due to its ruggedness, but it is like a damn beacon and the lens should have been recessed deeper into the housing.)
For current armed professionals like SWAT Snipers or LE Designated Marksmen, it doesn’t hurt to carry ARDs and put them on when you are in a position where you need to reduce signature, i.e. barricaded subject perimeter work. A small piece of brown or Multicam gaffers tape can also be stuck somewhere on your kit and pasted over your MRDS and light lenses if you suddenly find yourself in that situation.