I just purchased a JB-20 but am thinking of returning it from Thomann to purchase a JB-75. In terms of sound quality, pickups and hardware, is there much difference between the two models or is it not noticeable with an average amp, especially if you are a beginner bass player who plays mostly alone in the bedroom? Is the weight of the latest manufactured batches of the JB-75 still around 12 lbs? JB-20 is very light. For those who have been able to play with both models, are there noticeable differences with the neck and fretboard as well?