I can feel the warm air coming out of the vent when the unit is running. It's just a weak push compared to the rest of the house and it's working in a square room with 3 outside walls. I had the ducts cleaned over the summer. The guy didn't say anything about potential problems. Not to say he didn't see any but giving me notification of such a thing was part of the job description.
DISCLAIMER: No balls were physically hurt during the reading of this post. Should redness and/or swelling occur consult your gynecologist immediately.