Over the last few weeks, I've come to appreciate the Minilogue XD much more. For the time being, I've been able to compare it to a Korg ARP Odyssey Module, and to my ears the XD stands up just fine. One problem, though, is that the VCA should have been assigned the AD envelope and the filter the ADSR - the reverse of the Odyssey. Fortunately, the Prologue has two complete four-stage envelopes. Aside from that, I find the Korg to be a very enjoyable instrument to program and play. I'd love to have a pair of modules controlled by a full-sized five-octave keyboard.
I hope Korg adds another model to the "Logue" line. It has great potential as a workhorse hybrid favoring the analogue side of things.
I would have liked a four stage filter envelope too, but for what I use the synth for, it's not a problem. What I do wish Korg could have done is make it a class compliant USB device. I'm not sure if it's an issue for Mac users, but on Windows the Korg driver has this issue where the synth must be in the first 10 USB device slots or its effectively not recognized, and while I am fine just using a MIDI cable, the editor/librarian seems to require it. There are registry hacks to reassign the driver order and what not, but sooner or later if you have enough USB devices connected to the PC, it will eventually lose its mojo and require more messing with the registry. Why class compliance is difficult for a company the size of Korg I will never understand, but more than likely I will avoid other Korg products until I find they've changed their ways. I'd like to say I would buy an OpSix module if it emerged, but if it uses the same driver then I'd probably pass.
Aside from the USB thing -- its a spectacular little synth for the money and full of possibilities. I find its overall tone a bit colder than my Sequential stuff, but I think that's great because it tends to find its own spot in a mix, and differentiates itself nicely from my other synths. I've also noticed that it does plays well when layered with the Prophet 12, the fact it has far less voices doesn't really matter at all when it's playing a supplementary role in layers -- it might even be a plus.
The overall bang for buck makes it worth keeping even with the USB issue.