As I have posted on Head-Fi, my problem with conventional cupped or IEM phones is not being able to fully suspend the disbelief that I am listening to music from two small cups where most of the tiny sound is inside my head. Yes, there are some tricks used by headphone manufacturers to make the sound appear to surround your head but I would posit that if you were blindfolded and asked to identify the source of sound, you would correctly identify the sound coming either from loudspeakers or headphones every time, ignoring the feeling of having the phones on your head. So the issue is trying to reproduce the spatial and surface loudness aspects of listening to live music in a recording space, which IMO conventional cupped headphones cannot do correctly, even the best ones at that.
So the phones that best approximate the sound of live music in a performing space are the RAAL SR-1a/b nearfield ear monitors. No, they don't do this perfectly but they are the closest I have heard in this aspect. So any cupped phone or IEM, at least at this time, are seriously deficient in this aspect.