I'd like to "upgrade" the pickups in my MIA 62 RI stack knob jazz. The stock pickups are currently in there. My reasons for upgrading... The A & D strings are definitely lower volume than the E & G strings. I'd like a pickup that's more balanced overall. Also... the sound with these pickups seem to lack fullness or balls... 'bout the only way I can describe it. I'm currently thinking about Nordstrand NJ4 or NJ4SV pickups. How could I expect the sound to change with either of these pickups, and would the balance issue be resolved?