I currently fantasize about an Prophet 8, from the demos it sounds a lot more smooth than the Analog 4. I personally would like to have a synth which is capable to sound nice up to 8 khz with overtones.
I think about a Virus Desktop or Prophet Desktop. The Prophet even has a built in sequencer - but i dont know if i would use it that much, and sequence it from the Octatrack anyway.
I saw some youtube vids aswell - but i dont want a synth that generates “80ties” vibe. A lot depends on the time invested with that instrument - after a while i got more and more mileage out of the analog 4 - even more than i hoped. (guitar /violin / pipe like sounds besides the obvious bass etc.)