MAD ATC have a difficult job to do...two sets of parallel runways (36/18 R & L, 33/15 R & L) from which take-offs must be co-ordinated with landings to avoid conflicts during go-arounds, noise abatement restrictions after 23:00 LT reducing the number of runways available, stabalised approach criteria which vary between operators, high terrain to the North frequently resulting in G/S intercept from above and therefore grumpy pilots, adjacent light aircraft / Bizjet Airports, Pilots' often blocking the R/T requesting changes from the allocated landing runway so they can reduce taxy-in time, speed control on final not adhered to by pilots (because they don't trust ATC?) resulting in separation loss / go-arounds etc etc.
"Expect the unexpected" is a good maxim here, and that includes being ordered to go-around because the aircraft BEHIND is catching you up
