That sucks! I've actually been considering getting a second Monomachine since I realized how awesome Poly mode is, but then I think if I am going to do that, might as well expand the sonic palette and go for the Analog Four. But then I think, ugh, then I have to learn a new interface again and I won't get anything done for a while. Slippery slope, this gear business, haha.
As for the Polysix, it is an awesome synth, but I literally got that like 2 weeks before I got the 106 dropped in my lap out of the blue in a trade from another local I've had multiple dealings with, and immediately swapped them out so I could use the 106 for the DCO competition. Haven't really dug into it too much yet, but it's sweet spot seems to be smaller than the 106 for me, and it sounds more 'harsh' and 'dark' I guess, hard to describe - but night and day with the 106. Really like it, just need to sit down and program it a bit and see what I can make it do. Probably going to install a midi kit on it too. Luckily it was completely overhauled by the best tech in the city just before I got it, so aside from beat up end panels, it's perfect! Unsure if I want to go to the effort and expense to replace the wood, but we shall see.