In the day time I have found it to be fairly close. I can certainly zoom in 1,000 feet away with the 49225 and be verge of Identify/Recognize. I can read plates that far during the day.
At night, that number drops of substantially. At least half if not 75% Obviously a lot of factors come into play like amount of available light and shutter speed and other parameters.
If someone is standing still and I slow the shutter down to 1/3s at night, even then it would be tough to reach the DORI distances and movement will be a complete blur.