update
the westone are breaking in after 15 hr. of use the sound is changed, quite suddenly (!) and noticeably.
Changed in a good way, they have gained smoothness on mids and highs and details in the form of more subtle textures ( nuances ) appearing in the bass/midbass region
My brain is adpating too
and it's nice to adapt to the "in the head" stage - this if you get it ; I'm becoming more and more adapted and able to do it faster; some hours ago I literally didn't get the head stage though and the UM2 while incredible for a lot of factor on first impressions were sounding flat.
I can see as some can do it in a relatively short time and others (I hope few) hardly succeed in managing the in the ar sound/thing.
Now I'm using them mainly with Karma hpout now from a time . The sound comes out good and clean, after a bit of eq'ing I don't feel any need to add the ppa amp on the Karma out ( even if I'm sure adding it would improve the sound, the Karma+Um2 solution seems just right on it's own)
They're noticeably source dependent and responsive.
Plugging them to my home rig give a very bodied sound and the stage can be tremendously expanded.
Plugging them to the Karma give a slightly "lighter" sound signature (it suits them well too), so you can apply some eq. for "building" the stage over the stock sound signature of the Karma which is not uncolored.
Due to the low distortions they're capable of on moderate volumes and the way they handle the audio signal you can really set the karma eq as you like the most, you won't experience easy distortions and they'll be quite always nice to be listened.
Is very much important when you use them -and probably this apply to canalphones in general- to adjust the volume to the "very right" level , this mainly for hearing loss prevention.
Really.
Ears easily adapt to an higher volume if they receive few/no distortion - I experienced this and it's easy to experience.
To try it play a cd , set a volume that suits you in the start, then raise the volume relatively slowly during the first tracks and your ears will set in a relatively short time to the new level of sound , and you'll not be able to notice it is too much high after adaptation - you can do it a number of times and your ears will likely readapt to the sound level till a quite high sound volume. Reached this volume , again after some
minutes of listening (as volume readaptation seems to work on my ears on a minutes scale ) , lower the volume all-in-one to the first level you set in the start - your brain will notice it is too low: let adapt your ears/system some minutes and the volume will become right again, you will even be able to lower it again a bit and it'll be right.
My advice
to set a volume in the start - this dependent on the noise the environment around produce - then lower it a bit and let the ears adapt and keep this as a volume to listen to music for long periods of time (hours).
While I started the journey - on my karma as a source - with a volume of 12-13 peaking on 15-16 sometimes, now I'm set on a volume of 3-7/30 on quiet environments depending on the different moments of the day .
I still fatigue to find factors to dislike this earphones .. I'll report them if i find them