IMO it's nice to have two possible opening setups, which increases the number of alternatives. However, I find the way of deciding the opening setup slightly troubling. The problem is that in the first few moves the "correct" diagonal setup is chosen only if _both_ players agree, and _either_ of the players can force the "incorrect" parallel setup.
IMO it would be nicer to have this the other way around (so that either of the players can force the diagonal setup), but unfortunately the way in which the opening setup is "decided" is a natural consequence of the topology of the board, and cannot be changed in any natural way.
As an advocate of versatility I dislike the idea of changing reversi entirely into the normal othello with the fixed diagonal opening setup. IMO the best solution would be an option that when creating a new (instance of a) game or a tournament, the creator could specify whether to use a reversi-style setup with the diagonal/parallel decided by actual play, or create a game/tournament with the fixed diagonal opening setup.