I bought this a replacement for the less-than-impressive bar on my JEM Jr., and so far, it's been perfect all around.
I like to use the trem arm just tight enough to stay where I leave it, and whereas the JEM JR's original arm would need a huge amount of tightening torque on the nut to stay in place for 30 secs before coming loose, this one just works. And what's better, when tightened it doesn't bounce around in the bushings, so there's no pings and bangs when using really high gain lead tones.
It might be relatively expensive, but you get what you pay for.