Comparing the two directly: I find the Orions a little bit more comfortable, I just like the shorter nozzles better but expect most people to feel opposite. Orion has a very flat frequency response, treble and subbass are both rolled off, but mid-bass through lower treble are all fairly even. Io has more forward mids, which can make them a little shouty compared to Orion. Io has much more treble energy than Orion. The bass... Io is faster, will play a little lower, but is definitely recessed compared to Orions. In terms of soundstage and separation, Io is way ahead of Orion.