It's very personal. What I like may not be what you like. The results of my pairings may also be different to the results of yours if you are using different IEMs and DAP/DAC/amp.
U18T is a little too bright to me on stock and other cables I have.. TWT reduce the brightness a little which is perfect to my liking and what I've been looking for.. I recently auditioned cables costing a few times the cost of TWT but the warm touch they give to my U18T plugged to DX220 Max are either too much or too little compared to TWT to me. As for the rest like soundstage, levels of details it just improves in all aspects generally compared to other cables at around the same price or cost more. Some other high end cables give better soundstage, separation, speed and details but each other them have their pros and cons when paired to different equipment. Again, it all depends on the users' preferences. The pairing just made me keep listening.
Another thing is the separation on balanced plug is just nice to my liking, I don't like too much separation until the music is focused on separation, i.e. left, right, left right until I lose the focus on the vocals in certain tracks.
