I know a few observers (a couple who have ten years or more experience) who are now thinking that it's time to depart air ops. Reasons range from security and stability to better work life balance and money/promotion. One is actively looking to leave the police altogether, although that's to do with Winsor as much as NPAS.
Chatting to them they reckon they've had a good run on air ops, and don't want to be part of an national aerial missing persons and senior officer a75e covering service!
Part of the trouble is the uncertainty from a lack of hard information, or definite answers. Between NPAS and Winsor there is a very real chance that in a few short years there will be no experience, or possibly even police officers, on board police aircraft in the UK.