Interested to read BEagle's account of the fixed-wing method of upgrading to A2 - a LOT of time and training given to the candidate. I don't know if it's still the same (as I left the service some time ago), but in the rotary world (same instructor categorisation system) all preparation was done in the QHI's own time - no work-up or outside assistance, and preparation only possible using your own Staff Continuation Training. However, as my A2 was done while on the Chinook OCU I don't know if things were done differently at 2FTS; I don't think they were. The actual CFS Exam Wing assessment followed exactly the same procedure as for the QFIs.
There was also the massive kudos (yeah, right...
) of having 'cfs' after your name in the Air Force List for A2, and 'CFS' for A1.