A C525 rating covers all the C525 range - differences training is about avionics. The classic usues a very strainght forward FMS (if fitted) and small two screen EFIS whereas the 1,2 and 3 uses Proline 21 and the plus has FADEC.
Different models have different "drivers" for the Proline (Collins or Universal)
As a TRTO we can arrange differences training for a modest fee
Julian Telling
Head of Training (C525 & B200)