I think the outstanding quality of the Prophet 6 is it's bona fide analog sound. Obviously, the architecture is on the simple side, so it comes down to a raw more authentic sound. That's what its owners are primarily raving about, although it does have some interesting features. Sometimes a simple design makes you work harder and be more inventive with what is there, and with interesting results.
For now, my eight-voice Evolver takes up the digital slack, but I, too, would be interested in a DSI all-digital instrument comparable to a Wavestation. Who knows what the DSI side of the company will produce next? Sequential seems to have dominated the past year or more. In light of the obvious Sequential character, I would expect the DSI line to increasingly distinguish itself from old school type instruments. They couldn't go in a similar direction with both lines.
If I could have one wish, I would love to see an enlarged Prophet '08 - ten voices, four DCOs, a high pass filter, longer envelopes, some onboard effects. That would suit me perfectly. I've been hoping for that since before the Prophet 12 was released.