I would hold off until the next promo announcement for Q4. You are getting double/triple points right now with Hilton and if they offer the Free Nights Q4, I would go that route. Hiltons are better for me with availability in a lot of the places I go around the world but I would look at where I travel for work and make a decision based on that as well. (Of course, this is assuming the Hilton you are in right now is participating as many aren't.)