I once borrowed a PG-200 that was attached to a GR-700. I would play a note on the guitar, click hold on the foot pedal and spend time just looking for sounds. Although the JX-08 does not have the same solid feel as the PG-200, it has so much more functionality, including an arpeggiator, two channels and a sequencer. In addition to this, the sequencer has a random generator and random playback function. Together with built-in speaker, I like just sitting with it and poking it every now and then.
In Folklore: The Long Pond Studio Sessions, Taylor Swift talks about how Aaron Dessner gave her Silvertone guitar with a rubber bridge and how playing some instruments write their own songs. I had a similar experience with the JX-8P. I am yet to properly dig into the various pattern, but for me it provides a piece of randomness that was missing with the groovebox.