I had one
Man I used to love it.
Probably not great for your purposes - here's why.
I bought and used it as a DJ tool, which is what I think it was designed for.
Brilliant for that, I used to take it. maxed out at 4Mb, with a zip drive to my gigs, and I used to get some strange looks back in '97.
I spent a long time at home carefully making samples, getting the tempo spot on and editing really tight so that a loop would hold with the song it came from.
Playing out I'd synchronise the tempo using tap tempo on
the JS30, listening to the metronome beat on my headphones til it was locked to what I was playing out. The current equivalents are the Boss sp202/303/404 etc.
I'd throw loops or one shots over what I was playing.
You can also transpose a sample across the octave so you have it pitched up and down (but it didn't time stretch).
The sequencer sucks - no editing, limited quantise!
For making music you could use it as a basic midi sampler, and use your sequencer to fire stuff, or put some loops in and use them for inspiration. Also if you needed to play samples, announcements and one shots at gigs.
It's also cool for hands on control of making messed up really short loops - think fatboy slim rockerfellar skank, but really it's a dj tool for playing out.