What is all this about universals vs. customs ? Some among both perform excellently to my ears. It is obvious that customs are not always an upgrade. I do not even know why one would think so as some customs cost 200$ and some universals cost 1.5k$ (ok price is not everything but still.
The 1plus2 blows many customs out of the water technically. But several top end CIEMs (if you like their signature, and if your ears are ok to get customs - which I think is the case for the majority of people - and if you have access to a good audiologist) will be an upgrade from a good share of universals.
Customs have, IMO, specificities that make them better to some people. I for one think that the isolation is in general better, except if you use foam tips, which I do not. Besides, the comfort is superior for me, and I have several of both. Finally, customs have a larger area of contact with your canal making the music sometimes more visceral / immersive, BASED ON MY EXPERIENCE.
Music_4321, I think that you might be putting the emphasis on custom horror stories, whereas it is not as complicated as that, unless you have: no tolerance to customs / a bad audiologist / an dishonest CIEM company. Of course we hear the horror stories more than the stories that go smoothly, and refits are a pain. Do you really think if you were to conduct a survey on headfi, were people usually like to complain, you would get more people disatisfied with customs than people overall satisfied ?
But let us also remind people that for some people like me with huge canals or like my wife with minuscule canals, CIEMs is a better option.
Anyways, back to the SE846.