RAF here 20 years so far 10 to go. Avionincs techniain more commonaly known as a fairy, spent 5 Years ish a pan trash doing flight servicings, Best 5 years of my career had lots of fun, granted there was a fair amount of BS but in general all good. spent 5 years in a bay, before getting back on aircraft, now training AMMs how to Carry out flight servincings, hardly a day goes by with out me thinking what a cool job I have usually when walking along the Pan with various aircraft around me, although not a spotter so to speak I just love being and working around aircraft.
Like has already been said CIO go for the needs of the service not individual, when i first applied to join I was told I could only join as a driver, my reply was whats the point of joining the RAF if I can’t work on aircraft I can be a driver anywhere
Bear in mind each service has there fair share of Horror/feel good stories. Plus what has been said about Basic and trade training there is a lot of BS just grin and bare it and you’ll be fine as my grandad told me the day before I left “Keep you mouth shut and your Bowels open” and also bare in mind that depending on your choice you will be put in harms way.
Good luck in any decision you make.