I mean in terms between the two, I do feel Akira simply has better rewards and stronger resulting feedback off it. Overall, Akira just feels more versatile to the situation against most of the cast and better neutral with less strings attached. There is however different cases where certain matches pay off better with Kokoro than Akira. For example, I find Kokoro to be more effective of consistency to lower health bars towards Bayman than Akira. Akira can as well, but there is a lot more read factors here and player mindset from Bayman that can stop some of his offense. Kokoro has these options that leads into throw factors and gaining momentum. Against the entire cast, Akira seems more opt to win provided the player has good fundamentals to back him while playing as the character.
As for the tracking thing, to be quite blunt, I never really considered tracking to be a true legitimate problem for Akira with DOA because it's all based on reads in regards to tracking. If Akira "knows" you'll SS or abuse the SS system, you'd get hit hard from a guaranteed tracking setup launch he has. He doesn't have much tracking moves but yet those minimum tracking moves of his are no joke either. If he lands them, you'd lose 70+ health with no wall included, DOA's health is 300, if it lands on the wall you'd lose 103+ health. Not to mention that CH is still applied for side stepping. Akira could even throw people that SS so even throwing still applies. He just happens to be a character who's more obvious about it, but yet I don't consider that a main issue for DOA. If I had to pick a main issue for Akira (in terms of DOA), it's the fact that lots of his options comes from conditioning the opponent to fall for stuff and understanding the player while not screwing up. When someone says side step Akira more often, you are literally telling Akira to absorb that option and providing him the option to take advantage of it using the DOA's system. In fact, most of the cast can be stepped as well if they tossed a start-up attack that doesn't track with bad enders that also doesn't track. I don't find this to be a major major issue for Kokoro either.
Eliot and Leon for example, have linear moves. Though they also have moves with strings attached that retracks to a SS opponent. Leon's P6P/6PP retracks. Akira has 2 moves that retrack if the opponent SSs too early. The first attack will whiff, but the follow up will hit after the SS is over preventing the player to hold or commence an offensive action right after because Akira is still in the string animation from the follow ups. There's a lot of wrong for when an opponent side steps as well.
Though in VF, it's his common general weakness because the system favors him there as well as the other cast on that game.