The C-17A is indeed an excellent aeroplane - because beyond the basic aeroplane specification requirements, the practical needs of the end-user were taken into account during the design process.
If the RAF's A400M IPT aren't taking experienced ALM 'back end' views into consideration at an early stage in the programme, that would be very regrettable indeed. The lesson was learned when the C-17 was being developed; it remains equally valid for the A400M.