If W3 is any indication of the kind of thorough and polished content with all aspects of the game, it's completely understandable that this game is a long ways off.
Take your time and give us more Witcher content in the meantime CDPR!
Honestly, this is right. Big games with expansive worlds like this are awesome, but they take time to do right. Hell, people are already bitching about the problems in Witcher (hell, even I've had a few times I've noticed frame rate hiccups and if I've noticed them, they're bad enough to be outright lag cause I honestly don't notice that stuff unless it actually outright pauses the game for a second or two).
I don't think I've even seen a large world that's not had some issues (GTA V, every single Bethesda game, the Assassin's Creed games).
I'm fine with that, I realize they are huge games and it's hard to lock everything down in such a huge game. It's worth it for the games they put in a lot of effort and time into making (well at least the ones I've played).
But, point being is you want them to do a large game like that right, it's not going to happen in a year or two. Unless you want the game to turn into something like Assassin's Creed
.