I just got one. I'm in the midst of re-creating my Pro2 patches on it. Learning just how deep the Pro2 mod matrix is - JD-XA had more fixed paths.
It's my first Roland.
It's interesting that the analog section can be split into 4 parts. So if I want to have a 4 OSC mono with 4 LFOs, you can approximate that with 2 parts, have 2 more analog parts left over.... Oh and then a 64 voice VA. And the digital side is almost additive because you can put so many partials in there. Or you can play the digital side paraphonically through the analog filters.
The splits are nice, the vocoder is nice. As mentioned before, some of the resonances of the filters are very strange. It'll take some getting used to. The result actually sounds cool, you just have to mentally know that you can't go past 12 o'clock without it sounding very different.
I do see the value now in the limited number of waveforms of the Pro2. JD-XA has over 400 and while the variety is there, it takes a while to audition then all (you can skip by 10s).
Feels a bit like a toy (but doesn't sound like one). The Pro2 is built like a tank in comparison. I bought a used one and there are already scratches on the surface. I will likely buy the synthgraphics panels - if only to get the labels below the knobs instead of on top (dumb)
I've not got to the sequencer yet. It has a separate click output that is going to help with my live drummer.
Each Program stored is a full multi-program meaning you keep track of all 8 parts. There's only 256 programs total, which was also a small DSI realization I had - modern DSI synths have tons of patches! JD-XA only comes with maybe 64 factory programs. Seriously, just 64. Compare that to 400-500 for the Pro2 and Prophet 6. I know a lot of people don't want factory stuff, but it does serve a good demonstration and inspiration purpose if you ask me.
The choice of multi-fx on the JD-XA is also astounding. There are so many! Each part has it's own multi-fx and there a 2 what they call total FX over the whole program.
Small note, of the multi-fx is a "slicer". Just that multi-effect itself created something I have been trying to do on the Pro2 for 18 months with no success using the Pro2 sequencer - i.e. slice up a polyphonic patch with a rhythmic pattern. I could never get the Pro2 sequencer to do that - even after they decoupled Track1 from the note, it still didn't work properly with paraphonic patches.
I'll report back more later.