Managed to get my grubby paws on a preview of the Domains at War basic rules today, and they look pretty good! Simple / abstracted mass combat turns are mixed with PC actions against enemy units, where the scale is normal and it's you and your buddies against 300 goblins with spears. There's been some concern that engagements of this size (party vs several hundred enemies) will take a long time to resolve, but I suspect that they really won't. Powered by domain, hijink, and trade income, the average party level is starting to shift up towards 6 or 7 (7s: Tim's fighter, Tom's wizard, Drew's assassin. 6s: Matt's venturer, Drew's cleric. 5s: Tom's crocodile-man, Jared's bard. 4s: Alex's wizard). Tom just finished researching and repertoiring fireball, and the combination of cleave and damage bonus that the fighter and assassin can put out should let them demolish 1-HD foes in industrial quantities. Drew's a level from getting Flame Strike, and hell even sleep can drop a whole squad of humanoids. The other saving grace is morale; you probably only have to kill 150 goblins or so before the rest break and run. If you include champions and subchieftains in the units, then there's another avenue to break morale too.
On the other hand, I am a little concerned about PC survivability in the face of many, many attacks per round (and let me tell you, if I'm concerned about survivability, it might be serious). Lots of attacks means that even against plated-fighters with high HP, it's quite possible to catch enough incoming fire to get killed. So... I guess people will have to be clever. The standard answer for ACKS, really - if you're having trouble, quit being stupid (I have a good story along these lines - suffice to say that they were trying to clear two ankheg lairs, and stupidity was had, dwarves were eaten, tactics were revised, and then no further casualties were suffered). Also impressed with the XP and loot rules; there's quite an incentive for pursuing mass battles in favor of dungeoneering. Which is good, because that's kind of what we need right about now, as the Razors prepare for all-out war against the witches who have taken up residence in the Bleak Academy and their beastman allies.
So yeah! Looking forward to testing these on Sunday. Will report back in sufficiently general terms as to not spoil anything :P