Few things I have noticed...
I prefer the feel of the larger 80-90's body. I guess it is the fender in me but I like the mass of the larger body.
I think I prefer the slightly darker tone of the 4003, but both are awesome and I like that each has a slightly unique voice.
The 72 still has the nicest neck of any bass I have played. I think I prefer it's slightly thicker size to the 96. Tough choice though.
I find the tone on both basses is a little more muffled with both pickups on full. Rolling the volume of one back really lets the other's tone shine.
All in all... buying both was a great decision. Love the feel, looks and tone. Such a great rock bass. The addition of my tube amp was also a big part of the whole deal... tubes and rics = perfection.

