There was a time I couldn't hear much difference between synthesizers other than the obvious. The subtleties were not somthing I was event listening to or even aware of.
Until I took a PLG-AN150 card out of a Yamaha AN200 groovebox/drumm machine and placed it into a Yamaha Motif. The card depends on the host's DA converter. The difference was obvious. The DA converters in the Motif were higher quality and that contributed to a direct enhancement to its sound. The overall fidelity of the PLG-AN150 card in the AN200 Groovebox sounded muted, like a thin wet cloth was placed over the sound. Once the card is in the Motif, it sounded much better. The synth engine is the same (amazing synth engine btw) but the other electronics had a lot to do with its sound.
I had a similar experience between a Akai Miniak (Alesis Ion/Micron). Its synth engine and filters were great... lots of character. But the over fidelity was poor. I sold it and replaced it with a Roland JD-990 which blew my mind. Really. The components delivering the JD-990 sound where premium quality. The Burr-Brown PCM61P DAC has a huge impact on its sound. Replace it with anything else will technically work, however its sound will not be the same.
I have the same opinion of the Kork Minilogue and Novation BassStation II. Greats synths with character, especially for their price. But the overall fidelity is nothing matched to others I have, specifically; Oberheim Matrix 1000, DSI Prophet 6, DSI Prophet REV 2 especially.
The REV2 is likely the result of iterative improvements in the analog summing of voices, possibly higher quality op amps since the P'08 was designed at a time when DSI had to keep the cost down as much as possible with what was available to him at the time.
Again, not an expert, but the REV2, while patch compatible to the P'08, is essentially a new synth with higher speed processors to handle 64 LFOs, 48 envelopes, and realtime modulations to a DSP for the effects. The only similarity between the two is the filter, it's the most significant piece that attributes the character of its sound.