Maybe the Rockets have more of that resonant fullness that people like? As opposed to the tight accurate bass of the M60s. I've never heard any of the Rockets, but they must be pretty decent - people like them.
Hope I don't get flamed again here as this borders on a political statement (though it is highly germane to this discussion), but didn't we learn in consumer ed to make our purchasing decisions based on the social costs - as well as the personal costs - of those decisions? Does everything we buy have to come from China?