Music can be a mite repetitive (there's the same tune for almost every fight, for instance), but it's decent enough. Voice acting is typically excellent.
Of the newer Yakuza titles, Kiwami is the oldest and therefore the least visually accomplished. It's still pretty polished and highly detailed, however, the odd pedestrian behaviour the only issue that persists from the other Yakuza games.
Like Yakuza 0, fight encounters in Kiwami remain a joy, as you beat thugs with bicycles, traffic cones and other items. Breathing in everything Kamurocho has to offer is all part of an engaging experience.
The storyline plays it straight, while 70-odd substories offer numerous diversions. Brawls with Majima are also fun, while mini-games and other activities will keep you occupied for hours on end.
A lot of overlap from Yakuza 0, you'll feel like you're doing a lot of the same stuff over again. That said, this is still a very solid achievement list.