Here is the response to that question from the last Q&A session:
ATR 42-600 / 72-600 -Timestamp Jorg -
Hans [Hartmann] is working directly with Asobo on the ATR 42- and 72-600. Making great progress. I think we will have him here maybe next time. I think it would be good to get an update. It’s our expert-level plane. It’s going to take a while to get it done to get it done, but progress is really good.
This is going to be a hard choice to pick between.
Hans Hartmann has an excellent reputation from the Digital Aviaton Fokkers through Aerosoft with the CRJ series and now the ATR.
On the other hand you have Milziv with its reputation for building numerous top quality aircraft such as its awesome B737-200, and too many prop aircraft to mention for FSX and its derivatives, and several top notch MSFS products like the Turbo Porter and Corsair.
Not often in flight simming do we get these kind of options.
Nope, its like the Junkers and Fokker. Asobo is building an ATR, MilViz is building one as well. MilViz is known for quality add-ons, Asobo is not (my opinion) but the guy they are partnering with is. Hard to say which is gonna be better. I have flown the -600 extensively in real life, I will check out both of them!