I believe the problem will come when deciding where to draw the line on when to winch and when not to. The argument about 'where geography suits' is going to mean the Peak District and some of Cumbria as well as scores of other places well inland away from SAR flights and with poor road access.
So, whilst there may be many occassions where it is difficult to land on but easy to winch with 10 to 50 feet of cable, where does the non-SAR trained crew stop and say no? This is the rescue fever that Vie speaks of, if you have a casualty on a steep hillside or cliff on a turbulent day in crappy weather and you have a winch on the side of the aircraft, do you go for it anyway and put the crew and casualty at more risk than on your normal operations or do you wait for a SAR crew?
Do your rearcrew acknowledge the extra personal risk involved in dangling 50 feet or more on a wire?
One argument is that 'If it saves one life then it is worth it' but the counter-argument is that 'If it costs one life then it is too expensive' must also be considered.
If an inexperienced winch-op (since he is the crucial element in winching, not the pilot) injures or kills his winchman and/or the casualty because the crew had a winch and didn't think they should wait for SAR, what damage will that do do the excellent reputation of Air Ambs across UK?
All helicopter pilots can hover over land but winch-opping is a specialist skill that requires lots of training and plenty of practice. If the charities want to fund it then crack on but don't expect miracles. If it were me, I would make sure they all did a full SAR winch-ops course with annual competency checks.