There is a difference, like you say (I owned an Axe-Fx). It sounded very good, especially the Plexi, but at the end of the day it sounds like a mic'd amp. You can't make it sound like an unmic'd cabinet, leading to lots of [1] discussion [2] about getting that 'in the room' sound [3]. It sounds pretty much exactly like what you would hear on a CD; it's definitely good at getting that studio mix sound.