I think this is a relevant topic specially thinking about the scope of SIII
Don't get me wrong, it's awesome that it's as big as it is, but even today I think it was a little bit of "too big", there are so many places and locations you can easily miss (even in my first playthrough I missed the pine arcade). I still don't think I've been to every place (not even talking about thousand building), but all the bars, restaurants, shops, barbers, etc.
In Shenmue, I felt that I knew every place, all the locals and shops, in Shenmue II I can't say that at all.