We only own at Waiohai, so that's the only place I have a definitive answer for, and the answer is no. You purchase either an ocean view or an island view (all the units are the same size and there's no lockoff), and there is a number noted in our deed, but over the years we've been placed in different buildings every time we've stayed.
You can request a particular unit number 30 days in advance of your reservation, though. We've had some luck with this.