I have the Nova and Orion. I have not done an A/B comparison of either with the Io, but I think that it is safe to say that the chosen tuning for each of these IEM's is unique. The Nova is less detailed (warmer?) than the Io. I use the Nova regularly at the office (320mp3>Lenova Thinkpad>JDS C5>Nova). The bass on the Io is very clean, and detailed...it grabs your attention. On the Nova, the bass is also nicely present, but is less precise...it is there but doesn't command attention...amorphous? The Orion is a flatter presentation than the Io...less emphasis on bass and treble, so the mids appear more forward than on the Io. Although, I do not find the mids to be lacking with the Io, or "hollow" as some reviewers have noted (I am not even sure what that means). The Io presents greater detail than the Nova and Orion. I would also characterize the Io as having a wider sound stage than either of the others. Although, the Orion is closer to the Io than the Nova in this regard. Not sure how helpful this was. If you like the Orion or Nova, I don't think you would necessarily be drawn to the sound of the Io. It is as different from the Orion and Nova as they are from each other.