As I mentioned, I have 2 laser designators, an ND-3 Sub-Zero 40mm and and ND-3 Sub-Zero 50mm.
No, the marketing is NOT lying. I can stand on the roof of my barn and shine a beam that DOES show up on my neighbors barn 3miles away (on a clear night). That is to say, my neighbor can see the dot on his barn (about 8-12" dia, he's never measured it, but his wife swears it's 8", he swears it's 12". Sounds like they've had this arguement before! haha). But at the end of the day, a 3 mile range for a DOT doesn't matter, because I dam sure can't see anything in my scope that far away. I bought these two because they claimed they had 400-500yrd+ visible ranges. I'll admit, they'll make an animals eyes pop like diamonds WAY out there, but if it's past 300-400yrds, it gets pretty hairy trying to tell whether it's a coyote, a coon, or one of my goats.
Maybe your eyes are better than mine, but frankly, to me it's a moot point. If I can't do any better than getting coyotes to come in closer than 300yrds at night, then I don't have any business trying to shoot at them in the first place.
I WILL admit, however, that when a laser designator says it has a 400yrd range, it probably actually has a 300-350yrd usable range, whereas if an incandescent lamp says it has a 350yrd range, you're probably only really going to get 200yrds at best, especially after you take the batteries a couple cycles, and put a few hours on the lamp. I will also admit that a green laser IS more visible than a a red ANYTHING, and the lasers are more uniform, rather than having bright spots and dim spots in the beam. Sometimes it's nice having the ability to "hover" above your target with just the dim halo shining their eyes, then dropping the center "bright spot" on them to shoot, but it's also handy to really get to see your target too.
But again, I have over a thousand bucks wrapped up in these TWO lasers, whereas a cheap incandescent like the Primos Nightblaster 350's get me almost as far, and only run about $100 (1/5 or less of the cost of a Sub-Zero). No, they're not as cool, and yes, they're big and heavy, but for $500, I can stand to carry a 6V battery around (mount it to the right side of your buttstock, you'll never know it's there).
Hindsight's 20/20 I guess....