Were the All-National 9.2-inch guns effective?

Were the 9.2-inch guns proposed for the All-National battleships any good?

They were fairly capable for their time, and 9.2-inch armament was also considered for cruiser designs of roughly 15,000 tons.

The viewer clarifies that the question concerns the 9.2-inch guns associated with the All-National battleship proposals. Those weapons were fairly capable for their time, and designers also considered 9.2-inch armament for cruisers. A roughly 15,000-ton cruiser design in Conway's material is offered as a tentative research pointer. The short exchange distinguishes this design-study weapon from the different shipboard gun problem first assumed from the question.