The common denominator here is that SF enthusiasts want your Extremas and are willing to trade current models to get them. I'd be very cautious about giving them up.
I've heard the Cremona Ms and love them, but based on what I've read, the Extremas have almost another octave of bass extension.
I've heard the Cremona Ms and love them, but based on what I've read, the Extremas have almost another octave of bass extension.