I assume this new MOD F90 will have a magnetic strip or chip in it, so I can move all my details from one Stn to another and check in at the Guardroom with a single 'swipe'. It will have my current vaccinations and other details on it, so I can just pitch up wherever I need to be and hand it over to the duty adminer for 'in-processing', whether he/she/it is Pongo/Fine upstanding RAF type/WAFU?
Now that would be handy, and I for one would not be particularly bothered if my rank was not shown, I would let my natural leadership and military bearing shine through!
In the great scheme of things, if it makes it easier to do our job, then great. If it change for changes sake and cost money that could be better spent elsewhere, then it is not great.