Thoughts on it?(compared to the other games)
As far as the variety of things you can do, and amount of content, it's the best of the bunch. You could get by playing this game exclusively for months.
For me though, it was a little too much. There were so many side-stories, and optional missions that it was a bit overwhelming. Each character's chapter almost felt like it's own game, so the whole thing didn't quite have the focus of the average Yakuza title.
One of the big things I like about the series, is that as far as RPGs go, they're pretty short (around 20hrs), have lots of action, and really well told stories. The length of this one hurts the pacing quite a bit, so it doesn't quite have the flow that the other games do.
5 is really good, but I'd probably rank it behind 2, 4 and the first game story-wise.
Really excited for Zero though. It seems like it'll be a bit more focused with only 2 characters.