Going slightly off topic, I got a pair of Etymotic ER4XR today and compared them to my SE846, and wow, I'm impressed.
When I first listened to the my ER4XR I was underwhelmed, but as my ears adjusted I began to understand the hype. They're like a microscope for listening to midrange frequencies, though they still sound balanced (after your ears adjust). They bring out unheard details in many well known tracks, and sound incredible with many types of music.
I compared them briefly to some of the IEMs I own. First I compared them to my Shure SE425 since they are similarly priced. The ER4XR are far superior in every way, providing more detailed mids and more bass. Next I compared them to my Shure SE846, which are quite a different beast, each with their own strengths. The SE846 is superior in the bass (especially the sub-bass) region and have a "warmer" sound, but the ER4XR definitely wins in the midrange, which is so detailed and smooth. It would be hard to say which is overall "better" since I enjoy them both equally - which is impressive when comparing a $350 IEM to a $1000 IEM. BTW, for testing I was using a Chord Mojo, though they both also sound good with just an iPhone 7 headphone adapter. I'm using SpinFit CP800-M tips with both, which are comfortable and give a good seal for my ears.
I expect switching between the SE846 and ER4XR will take a little adjusting each time, but it's worth it for the diversity in sound. I think I'm done buying IEMs for a long while, since between the two I feel my needs are well covered.