How Königsberg's 150 mm guns compare with 6-inch cruiser guns

How did Königsberg's 150 mm guns compare with the British and American 6-inch guns?

On paper they offered similar firing rates, greater range, and higher muzzle velocity, but fired lighter shells and had practical issues.

The German 150 mm gun has a semi-automatic breech with a vertical sliding block and a quoted rate of eight rounds per minute. Its paper advantages include greater maximum range and higher muzzle velocity. Its shells are lighter, with the largest quoted at about 100 pounds. Unspecified practical difficulties with the guns and ship complicate a favourable judgement based only on those figures.