Jarrett, you'll appreciate this...
I took the SB5000 and my older NYC Sadowsky JJ5 to a gig on Saturday and alternated them. I was playing through a buddy's Mesa M6/212 combo (oooooh I love those amps).
The SB of course is ash/ebony, 70's spacing, single coils, and the Sadowsky is ash/maple, 60's spacing, and also single coils. Both are two band with full passive mode, and vol-blend configs. The preamp is not super important here though, because I rarely if ever use EQ... maybe just a bit of bass when favoring the bridge, but there is some voicing/coloring happening even without doing that, so gotta' note it here.
I've gone through a lot of Sadowsky basses at this point, and at least for the ash/maple JJ5 spec, this is the bass by which I judge all other ash J basses (S/N 4098). The tone is rich and full, bright and punchy as all hell, and the B string is just friggin' deadly... I kid you not... it outperforms B strings on many other basses (including longer scales) in both focus and power... and this isn't just me talkin'... I have others, including TB'ers, who can back this up, having seen/heard at gigs, and having played it personally. Definitely a from-my-cold-dead-hands bass.
The SB is definitely WAY more of the 70's thing... the bridge pickup is a little thinner and a lot more aggressive, and the SB's voicing is definitely more sizzly... this is part due to the nature of the instrument (pickups, pickup spacing, and preamp) as well as the ebony board. The slap tone on the SB is sweeter, while the slap tone on the Sadowsky is more aggressive and cutting. The overall voicing the the Sadowsky is a bit more punchy through the mids... partly due to the 60's spacing, and partly due to the maple board and of course different preamps. I have to give the Sadowsky the edge on the B string... it is stronger, but the SB's B string is DAMN respectable... not lacking a thing.
Regarding note/string consistency... both basses have a "feature" I really love, and it's that the D and G strings don't disappear out from under you without digging in more to compensate. Seems like I've played a lot of basses... even high end ones... that do this. Not a ton, but enough I find myself altering my playing style a little to bring them out. Not necessary here.
One other thing I noticed is the SB has a little bit better sustain on the higher strings. I have a feeling the extra pound of weight over the Sadowsky and the much harder board are doing that.
Another practical note... both basses are also well shielded... doing very well in venues known to be "cruel" (when fully blended of course). This is something I'm VERY particular about.
So far the only fit/finish thing on mine is I'm feeling the glue line between the ebony board and the maple neck on the SB. I'll just shave/sand/wool it down as needed and it'll probably be fine, but FYI. Carvin does a great job of dealing with woods, but every luthier I've spoken to in recent years describes how it's getting harder and harder to get highly stable gaboon ebony these days, so I have a feeling that's what happened here... the ebony changed a bit. So far, no problems with neck stability... as far as having to mess with the truss rod more than usual, but I'll keep an eye on it.
Still very different basses in a lot of subjective ways... voicing, neck profile, aesthetics, etc, but the bottom line is, it's more or less what you've been reading about. Carvin's really got something special here, and if you're looking for a truly great interpretation of the 70's tone, you really need to check one out. I'm still really diggin' mine a LOT.