Pros: Great imaging, neutrality, clarity
Cons: Slightly too little bass, smallish soundstage
Beautifully designed IEMs. Great sounding (especially with instrumental/classical music). Very precise imaging. Very good instrument separation, but lacks large-scale soundstage - feels moreso like instruments are playing within a confined area outside/within your head - common to many IEMs (I may be too used to over the ear headphones...). Bass is not very strong, which is okay for a neutral IEM, BUT the bass is extremely "tight", fast, and punchy. Bass could use more extension into the low frequencies (i.e. little bass response for ~10-30Hz). Treble is very precise without becoming sibilant. Mids are not as impactful as some other IEMs, but give a nice "lushness" to the music that makes it more enjoyable over the long run.
Also, as other reviewers have said, the sound signature on these IEMs does not give you an initial "wow factor" that some of the higher treble/bass IEMs give you (e.g. PFE 232), but it grows on you and gives a better impression over long periods of listening.
Needs a very low impedance dac/amp combo due to these IEMs having very low impedance themselves.