I have several Rics. They're not the only basses that run 'stereo', but they're the best known.
I've experimented with the Ric-O-Sound. Ideally, in my opinion, it should be done with two amps one on either side of the drummer. That's too much gear to schlep around on a regular basis, and takes up a lot of stage space.
However, back in my pro days, my amp went out, so I plugged directly into the PA board to get through the gig. It sounded good, if a little weak on the low end. Since I was going straight into the board, I made a stereo cable and used two channels, panning them full left and right. I thought it sounded great, but I doubt anyone but me ever noticed. Most people aren't really into subtlety, they just want a beat they can dance to. I might use it when I record my next album. Again, probably no one will notice.