So i just plugged my cans in for the first time.
First, and don't let this scare you, but there is TERRIBLE hiss and static when the prime has no audio output. I don't know why. When the prime kicks off any sound, notification, music, youtube, anything, you can almost hear a "click" and the hiss goes completely silent right before the output starts.
EDIT: this may be feedback from my cans not having any audio input.
I've listened to some FLAC samples and some 320kbps mp3s that were converted from FLAC for my phone. So far i'm pretty impressed.
Dire Straits - Money for Nothing - FLAC
Dire Straits - Brothers in Arms - 320kbps MP3 from FLAC
Nickelback - Good times Gone (320kbps MP3)
Disturbed - Meaning of Life - 320kbps mp3 from FLAC
Loreena McKennit - Incantation - FLAC
I can't detect any flaws in the output. Dynamic range and detail i find to be at least on par with the capability of my RS160s...perhaps a slight "flatness" to mid-vocals, noticeable only with the loreena mckennitt track, upper range vocals are very crisp. Unfortunately i don't have any of my floorstanders wired up at the moment so that's about all the testing i can do.
I'll be curious to hear some impressions from someone with a better trained ear than myself.