About the Gain "thing", Airbus and Rockwell have a little "disagreement". During Rockwell tests, the manufacturer said that during the whole flight, the capabilites of the WX on AUTO GAIN/TILT were adequate for the entire flight. However, during some Airbus flight tests, the test pilots saw that flying on low levels sometimes was necessary to set manual GAIN, because of the "hiding" of significant weather during climb. Nowadays, you have a real "mess" on SOP os A320F about weather usage. Some radar you should set +8 gain passing FL 150, other 200, and others 250. In other words, a real mess