I am looking for a new 5 string fretless. I have a budget number in mind of 1000 to 1500. I will absolutely never purchase another Ibanez under any circumstance. I would prefer to get a Fretless Fender 5 string, but one can only get 2 out of 3 on that list. I also would prefer American made and that is a big point in the Carvin column. I also prefer a Ebony fingerboard. The Warwick recently came to the final two as I have liked them from afar and I am leaning toward a satin black finish on the bass. I can make arguments in my head for both and I can play neither in advance. I can make an argument for a $2000 bass too, but don't want to spend that at this time. In my mind it is one of these, so a compelling reason to look at something else will need to be made. I guess the question comes down to Chinese made Warwick or American made Carvin for about the same dollars. I plan to pull the trigger in one week or less.
I own a Carvin PB5 I got new and a Warwick Corvette Std Ash 5 (German made) I got used. Both basses are passive.
Not an a/b comparison for what you're asking, but I have to give it to the Carvin based on the hardware and electronic design and quality. I'll give a short review on the aspects that made a difference to me.
Machine heads:
While both of these basses have machine heads with 20:1 ratios, I've found Carvin's to be much smoother. In addition, I've had one break off of my Warwick before right at the base.
Nut Design:
While the just-a-nut on the Warwick is a cool concept, and proved handy when making set up adjustments, I find that it lacks contact with the neck and kills a bit of the sustain of the instrument. I prefer the Tusq nut on the Carvin.
That said, I did order my Carvin with custom strings, and they didn't cut the nut to match them. It isn't too big of a deal, and I didn't specify that when ordering, but it's something I would expect when ordering a new custom instrument.
Shielding:
Carvin uses copper shielding in their electronic cavities, while Warwick uses shielding paint. I'm not at all impressed with the shielding paint. I compared my corvette with my friends after he put in some copper tape and there was a very noticeable reduction in buzz with his.
Bridge Design:
Probably my biggest gripe with the Warwick is the 3d bridge. Just like the just-a-nut, it's a cool design that CAN make setting up the bass really easy but it limits your string options. I prefer kalium strings which have a short taper which makes setting up the bass difficult or impossible depending on how you like your action.
The Carvin bridge is simple, effective, and has a top load or string through option. Where the Warwick limits your string options, the Carvin expands them.
Other Notes:
This may not be applicable based on the design/wood choices of your bass, but the Warwick has a pretty substantial neck dive. The Carvin has a little dive to it, but it's hardly noticeable. Also, stock pickups on both basses are pretty decent. Neither bass is my main player so i've felt no need to change them out.
Crappy pic of the PB5 for good measure.