I haven't heard the Syncrony 2B's, but I have to say, after hearing the Ribbon on the MA Plat. M2's, I would have a hard time believing the PSB's could sound as nice, the M2's have some serious shoes to fill...
Please don't flame me here, I'm just speculating.. I would love to get some time with the 2B's or any of the Syncrony line as they have been talked up quite well..