I must admit that being allowed through Class D is a bit of a lottery...
I have been told to orbit 3 miles from the overhead at Doncaster whilst a C152 was on 'Finals'... He turned out to be on a 12 mile Final, and when he did make it to the runway he went around at 1500ft below my altitude.
On the other side of the coin, I wanted a transit around the outside of Liverpool Class D, and they almost insisted that I transit overhead the Liver Buildings and Docks area.
Also Manchester has been particularly obliging, letting me do a photo session around Joderal Bank and then on to Matlock, even though they were busy with heavy traffic.