You have made it clear you don't like them but there are clearly those who like the SE846, myself included. We clearly have different preferences. That is ok. Doesn't make either of us right or wrong.IMHO the Nura Trues outperform SHURE SE846 in pretty much everything, including separation/imaging. SE846 is pretty limited in that area, hated them, with the exception of the bass. It's pretty odd for a 4 driver configuration, but it's what it is. They sound veiled, congested and not high-end at all. The Nuras sound much more livelier, open and fun. How can 1 driver best 4? Of course it is possible.
So, concluding, I wouldn't pay more than 200€ for an SE846, let alone the SE215. Unfortunately I did and lost alot of money selling them near brand new. Obviously my opinion is just my opinion and can't match everyone's taste, but I was accostumed to 2000€+ IEMs like the LCD-i4, QDC Anole VX and others.
However, you also mentioned in a previous post that you paired the SE846 with a Fiio M15. I did a quick search and that DAP is listed as having an output impedance of approx. 1.1 ohm. When I read your first post, I remembered my reaction when I tried to reduce noise by using a certain popular attenuator which increased the OI to 1ohm...you really need an amp that has an output impedance below 1 ohm and as close to zero as possible. Unfortunately the SE846 is just a very picky and sensitive IEM. No secret, I really like mine.
This was part of my hesitation with getting the TW2 but ever since I got it, my other TWS have not been getting any love outside of calls.