I had been trying to sell my sub 37 ever since I got the Model D and had not really gotten any offers till recently. I found I was unable to sell it even though I do think the sound quality of the Mini Moog is better. It is the witchcraft thing that I missed about the sub 37 so I have just decided to keep both of them and my band mates are really happy about that.
Bottom line on the sub 37 (when using it for bass) is that it can be so freaking dark and mysterious and magical. It can make sub terranian base with its over driven filter which I think someone at Moog made a deal with the devil to create.....
What the Sub 37 can do and how it sounds should not be underestimated and is very powerful. It is very different from other Moog synths I have heard.
Here is how I am using my Sub 37 presently. Right now I am primarily running the Model D oscillators through the sub 37's filter system to get that really deep over driven muffled and burnt sound and doing it this way gives me access to both the Sub 37's Lfo's and the four pole filter setting on the filter. This way I can go from the bright punchy sound of the model d and with a quick adjustment send the D though the sub and go into that magical territory with the D's oscillators-- or I can use the sub as a standalone instrument where I think the PWM combined with feedback and overdrive make for some incredible rich and complex mid and high range sounds.
Bottom line for me is that I have finally realized I just need both of them along with my two Mother 32's. I think the Mothers are the least impressive in this lineup for my uses and I basically just use them for drones (I dont use sequencers in my music) At this point the only way I would sell my Sub 37 is if Moog started selling modules to add to my Model D and even then Andrew at Moog has told me that IF they sold modules it would not be the Sub 37's filter that would be used so it looks like I am keeping mine.
Edit- Upon second thought I dont think the guy at Moog said that directly-- what he said was that when they put filters in other gear like pedals etc they presently do not use and have no plans of using the Sub 37 filter. I think that is a mistake as that filter is different enough and unique enough to warrant being used in something.