Of all of the complaints about the 4003, I have never understood people complaining about the binding. It seems you'd have to unnaturally press your forearm into it for it to hurt.
Well you have to play a 2 hour gig with it to start to see what's up with it. Than another 2 hour gig and then another... and you'll get the idea...
But seriously, if your technique is to play towards the neck with the arm resting on the bass, it will start to dig into your forearm. If you don't rest your arm on it that way, of course, it won't be a bother.
The real problem with the binding though, is at the fretboard. If you ever need to refret the bass there's virtually no way to do it without tearing the hell out of the binding. Typically you'll see the new frets simply smashed in there with the edges covering up the chewed-up binding.
Not a mechanical problem, but it sure is ugly as sin after a refret.
Don't ask me why I know this.
A dress of the edges has to be done super carefully too to avoid passes over the binding and grubbing up the area at the frets.
The S model removes the binding at the fingerboard also, which solves the problem.
Not a huge deal, but something to be aware of if you really love the way the binding looks at the fretboard edges. It won't stay that way in the unlikely, but possible, event of a refret.
L