Had a chance to try out a Sequential PROPHET X for a couple of hours in total;
Though they don't clearly say so, it IS a successor model for my fave synth prophet12. More like a variant but still is designed perhaps with the sales failure of the p12 in mind.
Tone-wise, much like an ensoniq VFX is to a TS10, an outgoing kid p12 is to a grown up and matured pX.
p12 tends to sound harsh and aggressive, whereas pX sounds with great scale, profound depth, unfolding panorama view like an epic cinema.
Samples are with so high quality grain texture that you'll swear it's from a software sampler. They should be processed with synthesis and effects because that comes out great rather than just playing back the raw samples mindlessly like another ROMpler.
The twin DSP oscillators add deeper dimensions that are otherwise impossible from samples. Super Saw is from PRO2, which is a great addition.
The filter sounds very SSM!!! Very much reminding me of Emax and Emulators. Great feel, better than a dry Curtis Electronics.
The multi-effects sounds clear and deep too.
On the whole, the software sampler-like high quality convincing samples, with a mystery feel of the SSM-ish VCF, and profoundly rich sounding effects, make a pX a synth with sounds of in-depth scale and vast dimensions.
The cosmetic appearance looks very matured too, with dark feel, more sophisticated luminous button shapes than p12.
The sample edit screen has no graphical waveform rendering, but works superb with truncation and looping, all done via a highly abstract and symbolic representations like an 80s sampler.
Ensoniq EPS trick of having a single cycle sample loop and scan it through with a physical controller can be replicated with a pX. Great when playing chords, like a vocoder or even a bit like VariPhrase from Roland.
I finally understood the reason why it remains as a current model. I like it very much. It is a p12 with two of its DSP oscillators replaced with samples, coupled with deep multiplex synthesis.