Creator of Colemak-DH here, so might be biased! Soul and Colemak-DH are somewhat similar - in that they both recognise that the traditional left-hand finger-assignment scheme on traditional keyboards is broken, and both try to improve Colemak by fixing the issue some people have with overuse of the centre-column.
I think Soul's main advantage is that it keeps Z X C V unchanged (even if the finger assignment is different from traditional), and is probably a bit easier to transition to. But in other respects, I think Colemak-DH is better. Soul seems more tied to ANSI hardware in that it relies on the Qwerty B key, which if you are using the symmetric system, isn't ideal. Consequently, it leads to the issue with J and K you mentioned, but this also means it doesn't translate so well to ergo/matrix keyboards. Soul also scores worse on same-finger stats, but the difference isn't huge. Colemak-DH's handling of Z is not ideal for ANSI users, but Z is the rarest letter in English, so this is likely more a psychological drawback than a real one (most ANSI users assign Z to the Qwerty B key rather than the Fat-Z option).
I don't have any experience using Soul, but it does look fairly decent on the surface. Nonetheless, trying to be objective as I can, I still think Colemak-DH's approach makes more sense overall.