'Duty of Care anyone?'
we argued this topic along with every other one you could think of in order to keep the Heathrow FBU open, and to continue offering its services to people like yourself. All shot down in flames on the basis of cost.
Afpex (the internet offering) was created to provide the opportunity for pilots to file FPLs via the Internet, which was what the GA community in particular were asking for. In their infinite wisdom, however, NATS took this as an opportunity to reduce costs (?) and staffing by completely replacing the existing service with the new one, rather than combining the two, which would have genuinely improved the service, irrespective of who delivered it. By doing this, NATS has honoured its obligations under the ANO, and has (allegedly) saved money as a by-product.
As to whether the service is improved...
and as an addition, if you haven't done so already, have a read of the Flyer forums for a GA-based view on the matter since Jan09.