I still say DS depending on your lvl. I take all my alts there grouped with my druid and just run havoc thru there. I run around the zone grabbing every Loyalist faction mob i can get up to 20 of them, I have 125 points of ds on, regens, aura, heal pots, and start dropping Tectonic Quake when they all get there. It can be a pain in the ass sometimes to get a spell off while getting beat that much that fast, but I always get at least 1 cast off for all the faction hits. If i am using an alt, I just remove my ds, drop a small damage cast on them for the pulls, and a tectonic quake just before I drop the ae from the alt.
Faction hits are faction hits. It's still the same hit in DS that it is in Anquish. I am in an extremely high end raid guild, but even with the way we slaughter thru COA, I can drop a ton more mobs in DS much faster for faction.