Cruiser1,
Yes, fixed power scopes do tend to perform better in low light than variables of equal quality, because they have fewer lenses, so fewer air/glass surfaces to scatter light.
John,
As I'm sure you know, I own a Hensoldt 6-24x72. The glass is near flawless except for one thing: chromatic aberration. I have another Hensoldt and it shows the same chromatic aberration. As you noted above, magnification does play a role in low light hunting. I can magnify the image higher than a 56mm objective and still have a maximum exit pupil, thus, I'm theoretically able to make out more details of the target/game. Never having sat down and done a side by side test with my other Hensoldt, which has a 56mm objective, I can only presume the increased magnification would help.
