Most of the content/performance issues on 6 is just down to using a new engine, it runs fun on the PS4 Pro, though it could use some anti aliasing to smooth out the rough edges in the game.
Story is a matter of opinion. For the most part I loved it. The new characters (bar one) are excellent and the final scene in the ending is just brilliant. Its just a pity that a few choices in the final couple of chapters hurt the overall end of the story a bit (in my opinion). Then again, I've seen people take real offense to
in the game, while I didn't really see any issues with that. Its definitely got one of the most bizarre twists in the series late in the game that's for sure, not bad per se, just up there with the whole Osaka Castle bit in 2 in terms of suspension of disbelief.
Content wise people are quick to point out what's missing, but ignore that 6 actually adds a nice amount of new content to the game - the arcade for example is greatly expanded on with new games (Puyo Puyo and the amazing VF5), new difficulty settings for other arcade games that make them far more playable to people such as myself. Also, all returning mini games see significant changes whether it be in terms of presentation and mechanics - so Karaoke and Darts are perhaps the best they've ever been.
Side stories are less in number, but fully voiced and in my opinion much better in quality. There are quite a few here that are brilliant, and the voice acting helps add an extra emotional layer to them. Now if they can just do something about those stiff idle animations we'll be in business.
Combat again is complicated one. Its on the one hand less complicated than 0 or Kiwami due to only having one style, however it feels far more fluid both in animations and execution. Heat moves are all redone from scratch animations wise so we have a nice mix of new ones, and returning favourites. Weapons however are largely missing outside of knives, hammers, swords, crowbars etc. The lack of load times also add a nice new dimension to fights - having them take place in areas where you couldn't fight before - convenience store brawls never cease to entertain me!
Honestly the main issue with this game is that they decided to move engine on the end of Kiryu's story. If the devs had another year to develop the engine and build on what we already have I bet it'd be a different story. Might have been a better idea to have them release an side story instead last year using the engine to "test" it, and then released Yakuza 6 this year with more features.