We did add one to the bathroom - the plan all along. However, if I had to do it over again, I would have put it in the hall next to the shower. The FF is too powerful for the bathroom and doesn't get enough airflow under the door when it's closed. With the door closed it slows down the fan. Also, if you are in there doing your duty, it passes your nose on it's way out, as that fan really creates an airflow from the door to the roof and there is no escape.
Just some thoughts.