The upgrade system was an annoyance, yeah. "Right so I can use these items as components... but should I be saving them for anything else? Some of them are also available from 'creature comforts', does that mean they might be for a creature related sidequest or perhaps for strengthening Eidolons like in FF8 and others? Are some of them better sold for money so I can buy better components instead?" etc etc, this was going through my mind all the time.

And then that awful thing where you don't know how much EXP (or whatever) the component will give a specific weapon or armour until you press X on it - and on another component - and on another component - and on another component... so that you don't waste a component that gives 15000 to one item on something that only gets 4000 from it. Possibly one of the most tedious game mechanics since FF1's "find out the attributes by noting your character's existing attributes then equipping the new item and using maths" system.