Unfortunetly I can't find any area where IT03 has better quality than Oriolus (in term of sound and build quality), and Oriolus' treble is definitely better with micro detail and smoothness. Some people will praise IT03 fiting though.
Agree with MiddleSky. If anything to critique about the Oriolus between it and the IT03, it would be how much more solid the IT03 bass is... but IMO you sacrifice a lot of the open sound for heavier bass.
The oriolus' highs are not insanely extended like for example Campfire Audios offerings but ot makes up for it with a richer bass and more body to its mids.