Being a UAS product I am of course biased but:
1. I for one would probably not be in the RAF if it wasn't for the UAS. I always liked the idea of being an RAF Pilot but it wasn't until I was able to give it a go and see whether it was for me (and indeed whether I was for them) that I decided to join.
2. For those that DO join following UAS, it matters not when EFT is completed (indeed if it is completed prior to commissioning it is cheaper!)
3. It is better to chop pre-IOT than later!
4. Of course the RAF will always get enough people wanting to be aircrew, the question is whether we get a good mix and balance of individuals. There will always be a need for a graduate entry. The UAS is the best way of getting graduates to consider the RAF in the competitive job market that there is.
5. Finally, for those that don't join they will have a positive view of aviation and the military that will assist the service in many but unquantifiable ways. The 'value-added' for the military should not be under-estimated.
Bean-counters know the price of everything but the value of nothing!