All of my basses are built on either a P body of a Warmoth G4 (which is kinda like the G&L body - a sleeker Pish kinda body). My Jazz basses (pickups are jazz pickups in the usual 60's positions) are built on P bodies, and have P width necks. Fits my big hands better, I practice a fair amount sitting down (the P shape balances better), and.....a P just sits better on conventional guitar stands. Besides being "different", I see no real reason one would prefer a J body. Obviously my opinion, and you're entitled to yours, even if it's wrong. ;-)