I have a pair of these and it took a while before I could find a pair of tips that stayed in for the most part with ocassional but often pushing them in to maintain the seal with a minimum of discomfit.
I use them with the Crinacle PEQ although they are absolutely fine without this, the PEQ adds something but I'm not sure what I'd say refinement as a catchall term. So whether plugged into my PC listening to Spotify with Peace or straight into my phone the results are simply great.
I think I am becoming a headphone guy, I still enjoy my speakers, but for the obtainable volume, comfort, taking the room out of the equation, plus some great PEQ settings I really dig getting into the music with headfi, and despite the artificiality of the presentation (I listen with my eyes closed and see myself sitting in a dress circle balcony, or at a table in a club on the floor near the raised stage etc and it works for me.
These IEM's are spectacular
I can change up at anytime and my discrimination is probably lacking for what delineates good from great but at the moment I am enjoying the whole gamut.
AKG 371 with or without PEQ (prefer with but not fussed)
Hi-Fi Man H400i (2016) with or without PEQ (prefer with but not fussed)
Sennheiser HD6XX with or without (prefer with)
Audio-Technica ATH-AD900x Air with Crinacle PEQ (so good, so comfortable)
I gave up on my Stax Lambda ^'s after 40 years they seem to have given up the ghost with a channel imbalance on the right side and compared to any of the above they are a kind of weird sounding headphone, especially after listening to the Truth Hear IEM's.