DJX is a toy, that's sure. But it's very different from a groovebox....
For me, DJX looks like those 90's PSR Series small keyboards. A lot of musicians learned to play with those series, but I would never compare it with grooveboxes like MC 909, 505, or RM1X from Yamaha.
I think Roland's grooveboxes are incredible machines. And what about Electribes????
A groovebox is higly recommended if you are on dance scene and youy don't want to operate a computer on stage.
The weak part of grooveboxes is the sound. Edition and creation of pathces is not the best feature of the grooveboxes, but the operational part is OKl for me.
Connect thru MIDI
a MC-505 with the Roland Phantom, and you'll a powerful new instrument. You can play continuosly.
Or use
a Korg Karma, or a Motif, connected thru MIDI with the
16 tracks RM1X. Use the advantages of the RM1X operative functions combined with the sounds of the Motif.
I use on stage a 6 grooveboxes network (Mc 307,505,909, ER1, EA1), and I could not live without them...
I think is a question of application and your purposes....