Dion has played pretty well, better than I thought, but I still think some are way too high on him. I've been wrong before though.
You seem to be right in this series but I still think the shot blocking/floor spacing Ibaka provides is more important.
The interesting thing is Kanter/Adams played 127 minutes together all regular season; OKC was a +5 in those 127 minutes. They've already played 66 minutes together in the post-season, they're +25. 13 minutes in the first round, so a ton in this series. Not sure how much of it is opponent dependent.