S12 definitely, but I'm not convinces it's 2x better. That's the "problem" with TCZ - they set such a high bar for such a low price, you're hard-pressed to find an IEM that's better, and that's priced proportionally (not 10x more expensive for 2x subjective gain).
I think for some people just not needing an EQ is going to be worth that extra $40. Although compared to TCZ (and to my own taste), a bass boost is required, but out of the box it's not really lacking. Just toned down. After a bit of a low shelf all the lowest notes are there with pleasant oomph and rumble.
Otherwise the tonal balance is, to me, perfect, and overall I did not find anything that TCZ does better, other than deep bass extension out of the box.
The only bad thing about S12 is the cable, and it's really bad, I had no idea a cable can make my ears hurt so much. Luckily, the TCZ cable fits perfectly and with it I barely even feel I have IEMs on.
All in all this is a reasonably popular model, judging by how often it comes up in various reviews and comparisons - not quite at the Hexa level, but popular. And I can confirm that it's well worth a recommendation (for below $100 - perhaps not for the sticker price of 130).
Having said that, there is one thing that left me unhappy about this purchase. A few reviewrs one (not one or two) point out S12 as the benchmark in "technicality", e. g. resolution/detail retrieval, and I'm not feeling that at all. It's definitely no worse than TCS, but I don't feel it's better either. If anyone else reading this has S12/S12 Pro - I'd be very interested in your opinion.