I tried one a couple of years back, but I'm struggling to recall what I made of it. The neck pickup had shades of Rickenbacker to it, and there were some more Fender-ish tones in there too. Some of the settings combining pickups had a nice honk or grind to them as well, somewhat like a Danelectro Long Horn bass.
I recall that the bass felt surprisingly big, sitting down. The bridge sits in the middle of the body, so by the time you factor in the body and neck length you have a P-bass sized bass. I guess the bridge location encourages the player to play up near the bridge, which might change the tone slightly? By contrast my Mustang bass is just a smidge longer than a Telecaster guitar, and the bridge is right at the back of the body. This gives you a longer string length to position your right hand over for different timbres.
I think some pickups just don't work that well for bass. Lipsticks are quite sizzly, bright pickups with a fairly scooped EQ profile. They are also sensitive to changes in right hand attack, and I found the Rascal could be a bit 'spikey' with nasty transient peaks if you dug in too hard (on a bass where you have to totally re-learn what 'too hard' is). Couple this with a shortscale bass and you get a sort of dull rumble of bass frequencies, fragile glass-scratching treble response, and not a whole heap of sustain or a whole heap of mids to glue it all together. The bass wasn't short of low frequencies, but the whole sonic signature of the bass didn't seem like it would drive a band along.
So:
Yes you can make any bass versatile by adding three pickups and a wiring scheme with an easter egg that unlocks mythical extra tones. You could buy a Gibson EB-3 and route it for soapbars. However, three lipstick pickups will have an inherent spitty tone that can't be dialed out easily, and a short scale bass will have an inherent shortscale tone (usually less sustain, rumbly low mids). The Rascal also has the bridge in an unusual location that might encourage playing only in a certain style.
The Rascal would, in my opinion, make a great 'Tic Tac' bass with flatwounds, a heavy pick and a good compressor. What it wouldn't do, for me, would be a good fingerstyle bass that could kill anything from Stingrays to Rickenbackers at the flick of a switch.