I can only answer this from my perspective, which is "old school." I have two dual woofer towers and a subwoofer, and any one of these would pull the ceiling down if I tried to hang it. Which I would not do, because I like my home theater system to be a visceral as well as aural experience, so the woofers need to be in contact with the floor.
My speakers are not so big but is it ever a good idea to hang them on the ceiling however firm the reinforcements may be? They are currently in contact with the floor and they sound really great.