So, the new, second-hand phone is up and running. The old, second-hand phone may still be pressed into service whilst I am running. At least until the sweat soaking through the arm phone-holder finally destroys it.
The interface is slicker and the responses are quicker. And the camera gives much clearer pictures. And has a flash! And a "burst" facility. I reckon that it will be impossible to take a bad picture with it.
Unfortunately, I didn't use it today.