There is no doubt that for the UK Police Role it is the lead new type (closely followed by the MD 902) - just look at the numbers and the number of additional EC 135s to go into Police Service in the UK this year. However the best choice of machine is affected by the rules you have to operate to and the local conditions. For us the UK CAA requirements dictate twins and increasing pressure towards IFR approved - this is not necessarily the case in other more aviation friendly parts. UK police carry a lot of mission kit, pilot + 2 observers (usually) which is a heavy payload so in the UK you need a helicopter that can cope with this.
I fly it and I think it is great for police work - it has its idiosyncracies like any other type.
I too would be happy to give you more detailed thoughts if you like to contact me by email.
The EC 135 User Group is best contacted through N Wales Air Support Unit.