Hi Jeff,
That's an unfair comparison--but my ideal inverter would be PSW, stand alone, 12 volt and 3600 watts continuous.
I could start with one Victron and add a second one if need be. Magnum doesn't offer that feature. Don't get me wrong, I believe the Magnum is a great unit.
The Victron Quattro can be connected to dual 120 volt power sources. "More Power
Two AC inputs with integrated transfer switch. The Quattro can be connected to two independent AC sources, for example shore-side power and a generator, or two generators. The Quattro will automatically connect to the active source. "