Refering back to some earlier posts, in an ideal world we would all have all the equipment and all the training we really need. Obviously funding prevents this.
From my own experiences there have been plenty of occasions when I have been grateful for the ability to perform night HEMS, but only one where a winch would have been handy. In these days of limited funding, prioritisation is essential and I would strongly advocate sorting out a night capability before messing around with winches on Air Ambulances.
On the odd occassion a winch would be useful we have to just accept the delay in getting the guys who are equiped and trained to do it. This delay could of course be reduced by an appropriate and co-ordinated tasking policy for all emergency services aircraft.
On the subject of the Met Air Support Unit I beleive it's more of a chicken end egg question. Was there an actual requirement for winch fitted EC145s or was it more of "Blimey, I can't beleive they've actually found the £15 million! We'd better think of a way of using them now!".
Either way, they have the kit now and are certainly in the best position of any police unit to force a decision from the regulators. Good luck to them - it could be of benefit to us all in the long run.