the problem with multi switching/pickup basses is there is always a compromise in one or more positions.
on an L2500 for example, there are tons of combinations but only a few really useable sounds. series setting is the default/best sounding.
on a stingray H, the parallel setting is the default position and the other two aren't as good sounding.
on a PJ style bass, you get a scoop if you run them both together; if you favor the J PU, you usually get a volume drop/noise.
I've learned that the simpler the electronics, the better. for me, I like as pure a signal as possible and favor humbuckers because I hate noise.
one exception is my jazz but even it has noise cancelling PU's.