Prophet 600 has been one of my favorite synthesizers for a few years. I love its analog rawness and panel simplicity. This video gives a good sense of its sonic character.
I don't suppose Sequential will be sauntering down the re-issue road again, but this would be my first request.
While I understand how some folks oppose Sequential re-issues, I actually think that in the wake of Dave's passing, focusing on reissues makes a tremendous amount of sense for them right now. I have no doubt in my mind the Sequential team can innovate new products that are amazing, but the brand is going to be associated with Dave's design mind for at least another decade, and reissues are popular enough to provide a stable platform on which to innovate. Once something new and unfamiliar is created, there is a lot of inexpensive competition out there, so it becomes a bit of a stormy sea for buyers to choose. While there is inexpensive competition in the "ripoff" (not reissue) category, it is less of a threat because everyone knows it's not the real deal and that only Sequential can make Sequential products right.
The Prophet 5/10 Rev4 proved that Sequential could release a reissue that surpasses the original in feature set, at half the cost of a vintage unit. This is their strength right now, they should ride it with other vintage remakes.
Sequential's biggest competitor right now is Oberheim, which is no longer a competitor but a collaborator. Into one of these two brands is where I prefer to spend my synth money, when I can.