You can get the H100, its forward firing.
Its very hard to say whether or not there is a difference, mainly because there is never 2 subs made with the same everything except for driver position.
Some say the down firing subs have a great tactile response due to loading on the floor.
Others say front firing subs excel in music because they sound better in the high bass region.
When my DPS-12 is in movie mode it shakes me like no tomorrow, and its front firing and front ported(slot ported).
I personally think front firing AND front ported subwoofers are the best(or sealed). Subs that send all the bass energy forward. I feel they don't rely on the rear wall as much and they blend and disappear better. But, thats just my opinion.
SheepStar