I had the pleasure of using this system recently in a night descent into Quito. The approach is basically a downwind, base and final approach inside a steep box canyon. Put one side on EGPWS, the other on radar, and watched the canyon walls close in beside us. It is worth its weight in gold.
I remember when EGPWS came out, they did a presentation at an ALPA Air Safety Forum. They simply obtained the flightpath data from 5 famous CFIT accidents (Cali, Cheyenne (USAF C-130), and others) and showed what their product would have displayed to the pilots. It was chilling.