it boils down to point of reference
if you start from the line 6 generation, axe-fx is a dream come true.
if you started on modern tube amps from major manufacturers and primarily like heavy tones, you might still dig axe fully.
if you started 30-40 years ago + on tube amps and have actually spent time with the vintage classics and ultra boutiques, axe may not float your boat.
for example, you can convince yourself a leslie sim pedal is just as good as the real thing, until you sit in front of a real leslie. but if you don't know what a real leslie sounds like and plays like, the pedals will do the job.
i spent the day with a hammond xk-c3. great b3 controller with very convincing sounds,
but without the real leslie 2 rotating speaker box it aint the goods.
that said i gotta get me one of these: