Subwoofers - Front Firing or Down Firing - Which Sounds Best?


Any advantage to woofer cone facing toward listener as opposed to firing down to the floor? Thinking of upgrading my 20 year old B&W ASW-650 sub to get that oh-so-pleasing belly message which lives in the 20-ish Hz range (very rare I know). SVS has the "tube" subwoofer (PC-2000) at a reasonable price. Just wondering if the floor-firing model would disappoint? Wouldn't want the hassle of returning if it did. Any opinions? Current users? Thanks. 
128x128dweller
How does this sound: My B&W "12 inch" ASW-650 plus a spiffy Polk 12 incher recently purchased for HT and the four six-inch woofers in my B&W 804d3s? Is this "swarm" enough? If it works, I could swap the B&W for HT duty and get another Polk (for symmetry) for the main two channel system. I'd be losing the plant stand, however.
Great start!
Worth losing the plant stand.
Don't worry about symmetry. Unless you mean visually.


One 15" can give you what you want?
If you want good bass in one position only and a wife bitchin' about the whole house booming/pressurized, have at it.
It's just me and the sweet spot fuzzy. Going to give the "swarm" a try first.