BEagle makes a valid point about the experience of the instructors and the RAF did itself no favours in sticking sim instructors in the job when they had never flown the aircraft or operated in the role. However, now it has all changed with Thales running most of the sims and BWoS a few and they can draw their instructors from ex-aircrew and instructors on type, usually with loads of experience and approaching retirement.
It is also the case now that the company running the simulator has a vested interest in improving both the technical and operational realism of training. I believe as a result we are going to see the RAF get better value from simulation.