This series is something special.
But yeah, Yakuza 5 really is the PS3 game where they SIGNIFICANTLY upped their facial animation game. Yakuza 0 and Yakuza: Ishin on the PS3 are no slouches either, but because they also have PS4 versions, they get overshadowed.
Going from Y0 to Y5 isn't an issue, it's the PS2 games where the real issues arise. And now we've got remakes so that's not an issue!!