Down and dirty, only actual “gear” being asked of, I’d say the Regman regulator. That thing is an air saver, a big assist in chronograph testing, and a joy to use target shooting while tethered to the tank. If this tread were re asked as what we find to be the best tool used for air gunning, the Regman wins again, as it truly is a tool.
And yes, back to having property to shoot, that is precious, as especially now when asked(ordered) to stay isolated at home, I would go crazy if I couldn’t drive out to a range or find my favorite place to shoot is over populated with other shooters.