I have three different scopes I use to check rifles with shooting issues I can't readily pinpoint, usually in the form of unexplainable flyers or wandering groups.
The 35 year old VXIII, fixed 4X, is one the scopes set aside because its 40 mm Objective will easily clear most barrels in low or medium rings, with 1 inch bores.
I also have a fixed 4X Burriss, with a 30 mm tube and a Zeiss with a 34mm tube.
All three of these are set aside because they just don't fail under any extremes, from heavy recoil to weather.
Of all three of these scopes, the Leupold likely has the least light transmission capabilities, but more than adequate for "legal light conditions."
When I purchased this scope, it had severe parallax issues, and sent it to Korth for replacement or repair. They replaced the Ocular lens and adjusted the angle on the Objective lens, which they believed was likely set up wrong in the factory. It happens.
I've had a few dozen VXIII scopes over the years, sold most of them, because I just had more than I would need. The units I've kept will be part of my inheritance legacy when I pass.
The tech in the VXIII scopes is very old. The lens quality is quite good, but they haven't upgraded the lenses with the rare earth coatings that allow better light transmission.
Even some of the newer scopes of lesser quality than the Leupolds have more rare earth coatings or glass made along with rare earth supplements. That being said, those lenses may not be as finely ground for sharper clarity, and the uninitiated observer may not be able to discern the differences because of the brighter image.