What’re y’all’s opinion on all forward facing subs vs. one facing the other way?
The biggest advantage of alternating the driver orientation is weight distribution. If you are building triples or quads and placing them on carpet, the more even weight distribution will make them more stable.
The biggest disadvantage is that it makes the wiring more complicated. If you are using solid core wire, fishing the wire between the front and back of the baffles is a bit of a pain.
If I was building duals (or even triples on hard floors), I wouldn't bother with alternating the drivers. I don't think there is any difference in sound quality.