My point of comparisons is trying to place where the Phonak sit relative to other universal IEM. The only IEM I have heard that I like more than the Phonak are my custom IEM and my Westone 3, with the Image X10 and Nuforce NE-7M closely below that. I'm not sure any of the others are worth messing with anymore. That is meant as high praise for the Phonak.
To me, the Phonak do some things better than the Image X10 and other things just as well, and I would prefer them more than the X10 in general because of the uncolored bass and lower mids, and more extended treble. This is important because I felt the X10 were better than the stock SE530 and Triple.fi 10 Pro, as well as most other universal IEM costing less. What I am looking for in an IEM is the ability to be exquisitely transparent and get out of the way of the music, with natural tone, and power and conveyance of the real performance. Previously I thought that in an IEM that experience could only be obtained by the UE11 Pro, based on reports I've read. Then I got my Westone 3 and that changed.
I feel my Westone 3 are at the top of the heap with a fully immersive and involving transportation into the performance, and sounds as impressive as an Edition 9 but in an IEM package (with iMod/Vcaps/Pico). They can be almost mesmerizing like the Edition 9, and you get lost in the performance until the CD is over. They bring the weight and presence of the performance to me. Live performances can have a visceral effect on the listener, and the Westone 3 are the first universal IEM to bring me that full size power and intensity. I knew that was the case when I heard them the first time in Oct 2007, during a visit to Westone when I brought my SE530 with me and compared the two.
As others have stated, with the wrong earphone tips, the wrong ear position or the wrong source/amp the W3 can have an over-bearing bass. For others that can result in sibilance instead, or both. But I think the majority of W3 listeners feel the way I do, and I understand that not everyone does - that is why we have choices. Some people gravitate toward HD650 and others gravitate toward K701, some to the Edition 9 or to the Stax SR-007. We'll never solve that argument about which is better. Same with IEM.
Back to the Phonak. After listening to them since Friday, so far I feel the Phonak belong in the top tier Universal IEM, alongside the likes of Image X10, SE530, Triple.fi 10 Pro, ER4, and only beaten by the Westone 3 (or my custom IEM). For those not planning to spend $400 on an IEM, I see no point in spending $300 on SE530 or Triple.fi, when the Phonak can be had for half that cost. The SE530 were very transparent but lacked treble extension, and the Triple.fi had strong bass and treble, but lacked transparency to me. I don't have specific complaints about the Phonak Audeo yet, although I may find something later, but for now they are my "go to iPhone IEM with mic". If anything happens to them I will be happy to use my NE-7M as backup without complaint as well.