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
If you live on a ground floor ...Step 1 Buy a chainsaw /Step 2 Cut a hole large enough to house your hi-fi on through the floor /Step 3 Pour concrete in the hole to create a stand for hi-fi /Step 4 enjoy/ or repurpose your fireplace.
Get 2 subs. If your speakers could go as low as you wanted, there would be a driver in each speaker to accomplish that. For a few years I tried to integrate a single sub in my system, different ways of connecting it, even different subs, always fiddling with settings, taking it in and out of the equation. Then I got 2 down-firing subs, placed them on the outside edge (not touching) close to each speaker, on tile squares (as speakers). Tried to place them as close as I could if they were actually part of the speakers. Problem solved. They sound great and very well integrated. I am not a big bass fan at all. My speakers are rated down to 38hz. Just needed that little extra low if it is part of the recording. I am sure all the other suggestions are great, this was just my experience with 2 vs. 1. Have fun!
I have had two rear firing subs placed between my speakers for years.  As I started more critical listening, I noticed dips.  I purchased corner bass traps.  This really evened out the response.  Then I talked to GIK and have purchased bass traps which go on the front wall at floor level.  The subs will fire bass into these traps first.  Panels are about 16 inches away from the ports of the subs  I was assured that this will only improve the bass not reduce it.  Actually the first reflection panels and rear diffusion panels are also listed as bass traps as well as higher frequencies.  I will be interested to see my outcome.  They arrive in mid June.  COVID has helped GIK with orders!
Syzygy subs, fires front or down, your choice, control from your seat, and EQ. Sealed and fast.