Well I picked up a Muse recently. Now I'm considering selling my OB-6 because I really don't need two analog polysynths. The Muse is pretty much everything I've wanted in a polysynth.
It sounds huge, it sounds wilder than the OB-6. Side by side the OB-6 sounds more organized, tidier. I've been replicating patches made on my OB-6 on the Muse and it's pretty easy to get close except for patches I've made on the OB-6 with the filter type set somewhere between LP and Notch, or patches that modulate that knob. And I realised that I do both of those things a lot when programming the OB-6.
The OB-6 has that sound, though, with the top end fizz. The Muse has an icy top end, kind of shiny, and can get resonant, a little boomy, in the low mids even with resonance turned down. I get why they put an extra HP filter at the end of the signal path.
My Muse is not as buggy as some reports I've read. The tuning is fine, everything works. I haven't heard the chirping someone posted about at GS, I haven't had freezes or lock-ups. The build quality seems a slight cut above the OB-6, it's solid.
I have had a few stuck notes. When sending MIDI from Logic the problem was solved in Logic by checking the box to send cc123 (I think?), note off. But I also had stuck notes using the internal sequencer. I made my own favorites bank and eliminated any of the patches that were getting stuck (there were two) and any sequences that caused stuck notes (three) and I haven't had the issue since. But I'm wary of it.
Some of the OG presets seem to highlight problems and appear to have been created before the synth OS was finished. There are presets with clicking LFOs and those clicks can be eliminated easily with the current OS. I felt that while some of the presets are very sweet, many of the sequences are unmusically confusing to say the least.
I have a "good" OB-6 with no issues, no wobbly knobs. It's a D.S.I. version, I like that Dave's signature is on the synth. It does have a very different sound from the Muse but I just don't know if I'll play the OB-6 much anymore. It's appeared in every track we've recorded since we bought it. I just don't know. I'll keep it a while, anyway, to make sure the Muse is solid. Rambling thoughts...