I've only just started in Wilderness myself, but my impression is that there are lots of prominent bugs that still need to be stamped out. It seems like every few minutes somebody in general chat asks why a quest turn-in doesn't work or why they can't enter a cave to access one quest without triggering another. Further complicating the frustrations is that fact that players can't copy their characters to PTRs manually. They're populated with copies of a given server, so advanced players who might otherwise be able to provide valuable feedback are barred from contributing by this arbitrary limitation. These are the sort of things that can keep people from resubscribing, and moving to other, newer offerings.