I don't have a super mini, just a regular mini from 2013, but I've ran many Haas VF mills over the years including a recent brand new VF4. A problem with Haas mills in general, regarding part quality, is that they leave small witness marks on parts whenever the axes change directions, so at the quadrants of circles, corner radii, etc. It's not ideal for cosmetic parts or when you are making a "lathe part" on your mill. Also the Z height tends to move a bit, not a lot but at least .001" over the course of a day in a temperature controlled environment, and also as tools heat up from use, making fine blends more difficult. The non dual contact spindle (non Big Plus) does not help the Z repeatability situation (or rigidity) and tools can get stuck in the spindle from heating up. The best Haas VMC, which I have never seen or used, would presumably be a VM series mill with HSK63A spindle, but a VM3 with that spindle option + any other options exceeds the base price of an Okuma GENOS M560-V for example. You'd have to be insane to go that Haas route, especially considering that they really don't age too well even if you take care of them, my impression is that they are pretty much toast after 10 years. And the recent change to corroding galvanized way covers does not exactly help with the value proposition of Haas machines.
A higher quality machine in roughly the same price class will perform better from day 1 and stay that way for much longer. Any machine with a dual contact spindle that doesn't leave marks at the quadrants is a big step up, and if it's also got better HSM motion, more spindle torque, and more rigidity, it's in a totally different class. I'd wager that the DN-S machines are better in all of those ways, but regarding the marks at the quadrants, I'd be interested in seeing a ball bar test. I presently have no experience with DN-S machines but they are on my short list for my next machine purchase. It's about time to upgrade the Mini and it ain't going to be another Haas.