If your main purpose in putting in a ceiling fan is the theory that
it's going to make a difference in the winter by bringing heat down
from the ceiling, I think you will be disappointed. I have one mounted
in my family room with a cathedral ceiling. If it makes any difference
in the winter, I sure can't tell. The room doesn't feel any warmer.
And, as Sqlit pointed out, occasionally you do get a draft from it,
that makes it feel colder. And yes, I have it running so the air is
drawn upward. If there is any real evidence that this works in the
real world, I'd like to see it.
Of course these fans can be great in the summer time.