The figures don't reflect the real difference.
The S&B Klassic is a Hungarian budget scope, with fixed parallax point, not great optics but good enough most of the time. Compare it with top optics, and the difference is day and night.
I am using March high mag zoom scopes, and they show a clear image when my eyes just see black. When it is a murky overcast day, they show a vivid picture than leaps out at you.
However, all high mag scopes needs more light on their high mag settings than on their low mag settings that one uses to take a shot. An IR sight does not suffer that problem.
For foxing or for rabbits, an IR sight is a no brainer, as no optical scope is going to get you on target in the middle of the night, unless you are into moonlit snowy fields.