Both of my bathrooms have dual Heat Lamp with Blower and Exhaust functionality. I never know when to use one or the other or both.
It seems silly to run both blower and exhaust as you're sucking out all the warm air that the heat lamp puts out. But say you're taking a shower...do you just put the exhaust fan on after you're done? My roommate only ever uses the Heat Lamp with Blower and I feel that isn't going to get the moisture out of the bathroom.