Indeed, a dilemma choosing gear for the right job. The ABM600 sounds good through the SVT212AV cab but the two Ashdown cabs stacked are higher and easier to hear on stage.
As you say both cabs are weighty but the SVT212AV is one lift only instead of carrying in two cabs.
The best I guess would be two SVT212AV cabs ( both with the V4B ) or one with the ABM600