If you know the subtension of a plex-type reticle, and have done some practicing, my experience is that wind-holds are certainly close enough for big game out to 500--if you're shooting in conditions where hunters who wouldn't even consider shooting over 500 might consider trying.
I think this is a very important point, as "shoot-able" wind is different than shooting under any and all conditions with a duplex.
For example, I've seen beginner dudes shoot well out to 300 yards with a 10 mph full value wind, using a duplex reticle. And with a 5 mph wind, they do OK at 400 - 500 yards. These are fairly mellow wind speeds, for those distances.
However, if it's howling and variable, those with graduated reticles (moa or mil on the horizontal) tend to do better. But, under those conditions, I think many would second guess the shot, on game. So for the hunters, the duplex may not be a handicap... since they won't be taking shots on game under conditions where the precision reticles excel. It's under the more difficult situations where tactical style reticles really become a big advantage.
