I skipped on Wildlands because I think it looks more fun with co-op - and I mostly play single player. It is still on my wishlist in Steam for when it goes on sale.
Definitely still some annoying quirks - I find stealth works better than it ever did in FC3, and I like that I can hide bodies now. But I think the AI is kind of really dumb from time to time (still deadly though). I think encounters could be toned down a little and it could be more difficult to outfit your character with decent weapons which would make the setting feel more dangerous and severe.
But - it is just so damn fun to play that I don't mind. I love that there is no towers and everything is found naturally now - and for whatever reason the side activities actually feel fun this time, more like quests than chores which is awesome.