Most of the gripes around 4003 center on the ergonomics, which is definitely an issue to some on the bound models. The 4003s models address most of those gripes, but otherwise sound identical. The push/pull “vintage/modern” tone knob adds some additional tones. I like the extra bling of triangle markers and binding, but the S models do have a clean simplicity. 2020 and up have the V2 bridge, which doesn’t lift, and has better intonation adjustment. The mute device is nearly useless unless you spend a good bit of time fiddling with it. Not something easily adjusted on the fly or on stage. They sound nothing like a Precision to my ears. A very versatile bass that can cop a P tone, but not vice versa. Nothing else really sounds like a Ric, and you either like that tone or you don’t. They had trouble with peeling finish issues for years, and their finish warranty is worthless ( you eat 1 way shipping to CA for ANY warranty repairs), so buy from a reputable dealer like Wildwood who usually go to bat for you with Ric or just accept returns on the occasional lemon. All in all, a nicely made, unique sounding bass, but not for everyone. Play one if even remotely possible, most people either love them or hate them immediately.