I already had Ares I and I have Ares II today. The Ares II has more extension and detailing in the treble if it is set to Ares I. I found the basses with higher definition in Ares II compared to Ares I as well. The middle of the Ares II are more defined, but in the same amount practically that in the Ares I. Overall the sound of the Ares II has more definition and sound stage than the Ares I. In terms of ergonomics, the Ares II improved considerably compared to Ares I.