Sharing a few amateur thoughts on the following cables paired with the Phantom.
Leonidas 4w. Bass and treble beautifully controlled and extended compared to the Ares II. Ares II felt raw and bold, Leonidas felt refined and and elegant, without lacking body. The Ares II at times exhibited a muddying of the mids from the emotional bass, and the Leonidas perfectly tames this, enhancing vocals tenfold. The Leonidas is also brighter and more transparent than the Ares II, providing a much cleaner separation and display. However, that comes at the slight loss of warmth and emotion which I might say takes a bit away from the timbre. That said, it was still extremely musical and balanced, thoroughly complementing the Phantom. I spent the most time listening to the Leonidas 4w because of how magnificent the synergy was.
Leonidas 8w. Bass and treble is equally beautifully controlled and extended like the 4w. However, the 8w is more laid back due to the slightly wider soundstage and less energetic tone. While the 8w didn't sound hollow, I felt like there was a little too much distance between you and the action. I much prefer the 4w to the 8w.
Lionheart 4w. I actually prefer this to the Leonidas 8w. Tonally, I think the Lionheart retains the Phantom signature the best. A little warmth helps the beautiful timbre that we all love. Unfortunately, I decided against the Lionheart because it was a bit too relaxed and laid-back for my liking. It didn't have that same punch and weight as the Leonidas 4w, even though it has very comparable extensions on both ends. The Leonidas is a little brighter and you get a bit more than what you lose.
Lionheart 8w. Did not like this at all because it was way too laid back.
Janus D. I should start off by saying that the cable is a beauty. The Janus controlled the bass extremely well and prevented any muddying of the mids. Vocals were on point and treble was perfectly extended. Compared to the Leonidas 4w, it is a little warmer which helped a little in the emotional display. But alas, at least to my ears, I wasn't hearing that micro detail and energy that the Leonidas so powerfully exhibited. The Janus was no slouch of course, and I would definitely recommend this pairing with the Phantom. But for what you're paying for this vs the Leonidas, and what you're getting, I couldn't help but think that the Leonidas was the wiser choice of the two. The Leonidas is more exciting, the Janus is more matured.
I had wanted to audition the M4L4 as well but unfortunately it is unavailable. However, I'm informed that it is brighter than the Leonidas and that's probably too bright for my liking anyway.
Disclaimer: The above are my amateur thoughts and should not be taken to be definitive.