Just received my A6! I'd ordered the left faceplate in ash but they made them both purple heart:
I actually do think the matched faceplates look classy and am enjoying them too much to RMA. As for the sound, my quick impression after < 48 hours of listening is that they are incredibly balanced across the musical spectrum. Initially I felt the highs lacked extension and sparkle, perhaps still feel that way on cymbal crashes BUT my main conclusion is that the highs are accurate and once one acclamates to it they sound somehow quite correct. Both male and female vocals are completely grain free and even on piano recordings that can be shrill on other IEM'S there is a beautiful, sibilance free naturalness to the A6. Similarly, the lows lack the visceral quality of some dynamics but man, they are so beautifully controlled, tuneful rather than bloated, and never bleed into the mids. As for these mids I am enjoying their quality very much, and the word that captures the sound best is "musical"...nothing boosted, nothing splashy or flashy but rather an overall coherence leading to the most balanced presentation I've ever heard.in an IEM.
As for soundstage, it is quite wide, fairly tall but perhaps not exceptionally deep. Instrument separation and placement is quite good, as is detail retrieval. As for sources, I can drive them very easily from my DX90 on mid-gain, or my iDSD micro at lowest IEM match setting and "eco" (low) gain. They do scale up a bit with the iDSD micro but I don't find the SQ to be markedly different.
Some have reported average lower volume settings to achieve satisfying listening levels with Adel-equiped IEM's, and in general from my brief experience with the A6 I agree. One can hope this will protect hearing but I recognize that only time will tell.
For comparison, I enjoy my Fidue A83''s as well but they are more akin to the house with curb appeal that may not satisfy one's needs for a longterm home. The A83 have more overt sparkle and can be good fun, but the trade off is that they can be shrill and brittle on some recordings, which leads to fatigue. More reminiscent of my Sennheiser HD600's, the A6 never present anything other than surpassing musicality, and I have stayed up too late the last two nights re-discovering my collection of 16 and 24 bit FLAC's...I can listen to the A6 for hours with no fatigue, just a calmly energizing enjoyment of the music.
Summary: After a very brief reaction of "Meh" I have quickly come to recognize and appreciate the understated but very special virtues of the A6. They are unassuming but do not mistake that for lack of exceptional quality. Key attributes are balance, musicality, detail retrieval and superior soundstage and instrument separation / placement (perhaps related to the Adel module). Above all is the A6's coherence. Even with complicated musical content they always remain under control. They may lack that "WOW" factor at first hearing and may not be best for certain genres or listeners for whom fun trumps accuracy. For me, however, I am enjoying the balanced, musical and coherent presentation of the A6 very much and look forward to more longterm listening.