A big thanks to everyone for their kind words...
She's definitely a very different animal from my Gibbys, starting with the neck profile and ending with sonic properties.
I utterly dislike the bridge and might have to do something about it, will report back once I'm done exploring my options, likely sometime this coming weekend.
The word on the street is that only 234 of the X-series basses were produced in 1983/84, I am trying to verify that piece of information but so far all the serial numbers lists I've come across indeed end with 234. This is # 81.
I still want a Starfire bass, though, to keep company to its '66 6-string sister. And a JS II fretless. And...