Also remember that the AGI is not "category" specific. There will be some (very few, but still some) questions about baloons, gliders, weight-shift control, rotorcraft, etc.
It's not tough to study (all the FAA pubs are available online of course) but you don't want to show up expecting all airplane questions and panic when you see something about retreating blade stall.
Of course, for the CFI, it is category specific - so no worries.