Construction: 6/10 - some minor flaws, but nothing too important.
Portability: 7.5/10 - a bit tedious to set up, but a whole heck of a lot easier to tote than the ol' "bull fiddle"!
Playability: 7/10
Tone: 7.5/10 - Nice "growl". Has a unique, semi-acoustic vibe.

In the lower price range, one can't really expect too much fancy wood and workmanship on an electric upright. The Carruthers is kind of a no-frills axe: not as stylish as some of the other stuff out there, but it gets the job done without busting the budget. The neck is made from two pieces of rather plain-looking maple, and the fingerboard is a nice, thick piece of ebony. The semi-hollow body is Alder with a nice, smooth finish. The hardware is simple and sturdy.

The Carruthers comes with a cordura nylon gig bag that lets you sling the instrument over one shoulder. It can easily be stowed in a variety of locations, including the front seat of an import car. Portability can't get a whole lot better for a 42" scale instrument.

Unlike on traditional uprights, the neck wood extends all the way to the end of the fingerboard. I had mixed feelings about this. On one hand, the lack of a "diving board" made for a more solid feel, fingering notes in the upper register, and it certainly made the bass appear more roadworthy. My plucking (right) hand, however was less than fully enthusiastic. The shallow depression routed in the side of the neck only went so far in providing the familiar feel of a real upright.

Overall, playability was good, with medium to low action.

The Carruthers has a screw-in "rib rest" to compensate for the lack of the traditional bass body. This kind of extension is necessary on most EUBs, and this one is relatively comfortable and solid. To put the bass in the gig bag, the extension needs to be removed and stowed in a provided cordura nylon pouch that gets stashed under the strings, between the neck and the bridge. (Make sure you don't misplace it, or you're screwed...)

The end pin is a piece of solid aluminum doweling with notched machined in the side. It's nice and sturdy, but alas, it doesn't provide the necessary height if you're over 6' tall! After scrounging for various different solutions, I finally cut a length of 3/4" anodized aluminum pipe that fit in the socket, stayed in place with the set screw, and didn't wobble too much. Phew! (My homemade end pin wouldn't fit all the way back in the bass; instead, I took it out, put it in a bow bag and stowed it up next to the fingerboard for transport.)

The pickup system is interesting: the solid maple bridge "floats" on two wooden bars, each of which hosts a set screw with a rubber tip. The rubber end contacts a piezo pickup element, embedded in the body wood. The pickup gets fed through an onboard preamp, complete with volume and treble/bass boost/cut.

In terms of sound, the Carruthers has a nice growling tone. The elaborate pickup system and the hollow body contribute a little bit towards an acoustic-type vibe, but ultimately, it does lack a certain boominess & natural delay that one associates with a real upright bass. Bowing sounds somewhat nasal. This isn't a major flaw, it's just the nature of the beast. A bass fiddle is an apple and an EUB is an orange.

The onboard EQ sounds decent, but it's not particularly potent. If you're wanting to drastically alter the sound, you might have to use an outboard EQ unit.

Onstage, the Carruthers worked best in acoustic-type settings (i.e. alongside acoustic guitars & mandolins). At high volume levels, it tended to get buried. Buy a Carruthers for the transportability, buy it for it's unique semi-acoustic vibe. Don't buy it to compete with loud drums and electric guitars.

I used a Carruthers SUB-1 for two years as my one and only upright bass. Although one prospective client apparently declined to hire me on the grounds that the bass "sounded weird", most fellow musicians and audience members had nothing but praise about the look and sound. (I suspect that the one dissenting client wasn't going to hire me, anyway.)