Summary: After comparing a bunch of headphones, I "almost" fell in love with the Audeo Phonak PFE112.
The mid range of this set is very smooth and high quality. The treble, while slightly laid back and soft, is very open and precise. Although these aren't the airiest set, the treble extends well, albeit at a slightly relaxing tone. The main downfall is the lack of bass. There is good extension into the sub bass, but only at very low levels.
Summary: From my point of view these are excellent, both in terms of sound and isolation, plus they look extremely elegant.
I am not a 'golden ear' and can't really say much about the harmonics and sound spectrum as I'm really a complete noob here. However even for me I think I'd like a bit more punchy and powerful bass. Nevertheless the sound is basically music to the ears.
I use the comply tips supplied which provide great isolation and comfort.