I am, by no means, an expert on these things but, I do know that a pickup generates sound by the vibration of the strings. When you consider fretted basses, the sound of a note is produced by depressing and plucking a string. The fret is metal and the bridge saddle is metal. Therefore, all you have is a metal to metal length of string that produces a sound (note). With the exception of the small screws that attach the pickup to the body, there is very little, if any, contact between the pickups and the body. And, most pickups have foam that further isolates the pickup from the wood of the body. So, when I read posts that promote maple fret boards over rosewood, swamp wood over alder bodies and hi-mass bridges, I kind of wonder what verifiable information there is to back them up. Maybe somebody knows and whose answer is verifiable. Until then, I will side with the type of strings, pickups and, of course plucking technique.