FM vs. 2.4ghz

ok the only thing i'm curious is, with 5 trucks how would they be setup diffrent? i bought a mx-3 fm radio w/model memory. i noticed quickley that i set my trucks up the exact same every time and it didn't matter what truck i ran. what options is everyone changing between cars. to me steering trim is pointless the middle is the middle
though i just got a nomadio with way more model memory
just curious why this is so important when does anyone have steering or throttle trim not setup towards the middle