Bearintheair,
I think you are right about the dual use helicopter, especially in ruralish low population density areas. I have never worked in a "pure" HEMS role, but observing what they have done, sometimes the helicopter is used to do things that arguably would be better done by a ground ambulance. An important consideration is to get deployment criteria right; it is wrong to waste money and resources whoever is paying and however much we like to fly. At the same time, it needs to be a reasonable foresight approach rather than the usual hindsight test so often beloved of critics. You can only make a decision on the basis of the information you have.
One reason why PAOC involvement in HEMS is beneficial at present is because of the ability of PAOC holders to do CASEVACs. For those not familiar, the PAOC conditions allow a police helicopter to land at ad hoc sites at night where there is a genuine threat to life to pick up an injured person for delivery to hospital. (Non-police HEMS has to obey the normal UK public transport rules that prohibit landing at unsurveyed unlit sites at night). This is possible because of the rule difference; it is also more sensible and safer because the police helicopter can use its TI, nightsun and NVG to allow its "passengers" to help to check the site for the pilot.
I have not begun to look at the proposals for the Public Service AOC yet. I just hope it is not like most other new regulations in the European arena : more regulation allowing us to do less and less at significantly greater cost.