Bought these to compliment my v30 and greenback-loaded cabinets and am not disappointed.
Fills the room in a different frequency compared to the v30. Less glassy, more grunty. Plays equally well with my regular D and drop B tuned guitars through a Peavey 5150 or a Jet City JCA22h. Have yet to try my Marshall, but these go well with the American high gain sound type amps.
Loud enough in a 212 setting with a pretty loud drummer and a guitar player that uses a 2x 212 configuration.
This will not replace your v30, but will compliment it, make no mistake.