Are they bad?
In my opinion they are not the best in the world, having suffered an engine explosion - the crankshaft failed, taking two cylinders through the top cowling, destroying much of both the top cowl and lower cowl with debris hitting and damaging the tailplane, followed shortly afterwards by a small fire due to a petrol line being severed. All of this was at FL100, flying IFR in the airway. The fire extinquisher system worked but due to the damage the aircraft was not able to hold level flight, the best was about 300fps sink with full power on the good engine. When this was sorted a mayday was transmitted to Madrid, the response was "standby" after a delay of a couple of minutes I transmitted again and was told "standby" after another minute or so a passing British airways flight tried to relay the message, he too was told to standby. Transmitting on box two on 121.5 brought the same voice also telling me to standby. A few minutes went by and the emergency was acknowledged. And yes, I did change my transponder to 7700 before the first call.
A safe landing was made at a military airfield some 30nm short of Madrid (the aircraft was too badly damaged to make Madrid) where I enquired if there was another emergency going on with Madrid at the same time - I was told no, its normally like that as its so busy.....