The body shape is actually slightly different, the heel is not only rounded but more symmetrical than the BN5, and it has 20 frets instead of 24. I find it has a deeper bottom than my BN5, even with the same tone and boost settings.
George can probably add to this explanation, and confirm that the reason he dropped the Studio model was that it wasn't enough different from the BN5 to justify.
Why did I buy it? It was in stock when I visited the shop one day, and I fell in love with the sound (and, to be honest, the colour!)
Studio vs. BN5
Because the Studio has 20 frets and the BN-5 has 22, to keep the scale length the same the Studio has more wood in the neck end of the body and less wood in the neck itself than on the BN-5 (shorter neck, larger body). What this difference means functionally is that the Studio has more of a P-bass sound, that is, more lower mid range and bottom. The people who buy Studios tend to be players who are really comfortable on Fender basses but who need a 5-string. When I warned one player that he might miss the two frets, he said, "there's no money up there."
The BN-5 is more like an evolved Fender Jazz bass. If you can imagine the difference between the sound of a Precision and a Jazz, you can figure out the difference between a Studio and a BN-5. Both instruments have identical pickups and wiring.


