So if my math is right, they only reason to choose the Triple points option (they make you choose one or the other, and you can't change back), is if you are Diamond, thus getting 40% points bonus AND your average hotel rate is $96 and up.
That would roughly get you 4032 points per stay, and then two stays would be more than the 8000 points you will get for two separate nights the other way.
ALSO, the triple points does not kick in until your SECOND stay, so the first stay would just be your normal points plus 40% for Diamond or + 25% for Platinum.