Yeah it takes a little while for me to appreciate the sound brought by the EX600 because it has a distinct sound signature considering I had only listened to the buds before that. For the IE80, it is right on because I pretty much knew what I expected.
I am glad I bought the EX600 first. If I bought the IE80, I probably would just settle down with it (because this was what I was looking for at that time) and never experience another sound signature like the EX600. They bring to me different sound for the music enjoyment. The IE80 brings the sound which is powerful, heavy, ocean-like, solid, hurricane windy, yet the EX600 brings the sound which is sexy, refined, crystal-clear, breezing. For vocal, the EX600 suits female while the IE80 suits male. Of course, this is only my experience.
I finally ordered the Yamaha EPH-100 ($115 from J&R) instead of the FTX90 for my son. Both IEM's are receiving good reviews from this community, but I went for the 100 primarily due to warranty concern. I also like the looks of the EPH100. Now my only concern is whether the sound isolation will endanger my son's safety when he has these walking outside.
The Denon d2000 should be in tomorrow if not today and the EPH100 will be in on Friday. Will keep you posted what I think of these over the weekend.