I've owned a Super P and Super P/J, both were superbly built and extremely comfortable on the shoulder. Loved the fanned frets and after initial trepidation, was delighted to find that they just felt right and natural.
The P/J in particular was a spectacular instrument, it was built for the Namm show and was the one featured in BGM a few years back.
The only problem and this was really more down to my technique, was that when using a plectrum, the pickup angle and positioning made it difficult to play in my usual style. When playing finger style or with thumb it wasn't an issue and perhaps with some adjusting of my technique, I could have overcome the problem.
Also, I always made it sound like a P bass and so, given that I've pretty much always played P bass style instruments, I just decided to stick with Fender and G&L, which suit my pick technique. Couldn't just have them sitting around for home noodling so they were sold.