I can rotate my shoulders past 90 degrees without thinking, which sometimes makes it difficult to get everything back to where it needs to be at impact. More and more, I try to stop my swing when my left shoulder hits my chin. If that's plenty of turn for me, then it's plenty for you. If I stop my shoulder turn at 90 degrees while rotating my right hip slightly behind me and keeping my left arm straight, there isn't a par 5 on earth I can't reach.