Interesting thread. I agree whole-heartedly with Dr Syn, and with Air Bus Driver regarding the use of the phraseology.
HD, I have to disagree with your second post. You appear (correct me if I'm wrong) to have fallen into the trap of thinking that R/T transmissions from aircraft are communications to you. That's correct, but not entirely. I know that MATS (and ICAO procedures) do not assume that crews listen to the transmissions of other aircraft, but this is a bad mistake (and one into which the French fell over their failed experiment in using Aeronautical English at CDG). Aircraft crews obtain an extraordinarily high proportion of their situational awareness from transmissions to and from other aircraft.
Use of either "Pan Pan" or "Mayday" will very rapidly relax all those fingers straining to push their respective PTT switches as soon as they can get a word in edgeways.
For this reason, if for no other, I would strongly advocate the use of the term.
Furthermore, where Ops Frequencies are often congested with people ordering bar uplifts, discussing schedule changes etc. etc., it may not be easy to get handling agents to order an ambulance to meet us on arrival on the ramp. The less bright among them will often have ordered an ambilift instead. If we can't get through to them, we know we can to you. Consider it a backhanded compliment - we trust you (most of the time
)!
PS brokenspectre - the answer to your question is no - an ambulance will turn out if requested, and the relative urgency gets through to the ambulance operators.