MidnighTempestI haven't heard the 1990, but my understanding is that the Amrion treble is not as harsh. I would definitley recommend demoing the Amiron before buying- while the treble isn't particularly hot, it does border on harsh. For me, it's an awesome headphone with great detail while maintaining a relaxing signature that I can listen to all day, which is only made easier by their superb comfort.
If you have narrowed it down between these two sets but are concerned about treble sensitivity, the Amiron is definitely the ticket.