My understanding of them is that they were never about transparent sound.
You're probably paying a premium for one or more of the following:
Cool design (the O2 looks pretty lame TBH)
Useful functions / features
Exotic technology that's cool to have (may not even affect SQ)
I'm pretty happy with the sound from the phone-out on my laptop :p
It's powerful enough to drive my full-sizers and quiet enough for CIEMs.