What on earth are you guys talking about? For the 100th time, headphones DO NOT HAVE SOUNDSTAGE!
Recordings may have soundstage. Headphones may have fake spatial effects, due to its design placing the driver too far from the ear. Any set of matched drivers placed on the ear (or in the ear canal) should give you the correct soundstage in the recording, if it has one.
Yes we know, but it's more 'soundstage in the context of headphones'. Compared to speakers of course, headphones do not have soundstage. But we're comparing apples to apples here.