In my room, at least, I can hear no difference in all listening positions. Can't remember who I spoke to at Axiom, but when I posed the same question, he said "it's orientation won't matter, as long as it's pointing toward the central listening position." As I've only had it for a few days, I haven't spent all the time I wanted critically listening, but as of now I honestly couldn't be happier.
A friend of mine has the VP100; when he brought it over, male voices actually sounded more nasal than with the M2. the VP-100 was more efficient, however; I had to recalibrate levels to match it properly as opposed to the M2.
