"Downfiring" is only good for subwoofers, which should only operate below 80 hz or so that cannot be localized.
Woofers can operate up to several hundred cycles and if these were "downfired", a lot of the upper bass/lower midrange would be shooting at the floor and sound muffled.
Empire tried something like this with their Grenadier series of speakers in the late 60'/early 70's and while the were physically gorgeous, they tended to have a muffled sound.
[edit]Thanks for the link to pics, nomo. Great minds think alike.