I am really very happy with my Icemaster 100 as I regularly crash to 28F and never have had a problem to reach that temperature. I can achieve that temperature with two vessels (CF10 conical and a 20 gallon bright tank) at the same time.
As you will read, other manufactures struggle to even reach 40F. Of course the excuses they give is that every situation is different. That may be true, but I have never read any post where someone complained about the Icemaster 100 not being able to crash below 40F.
It gets very hot in the summer in southern AZ so I brew in my game room in a controlled environment where the temperature is 70F - 76F throughout the year. The Icemaster 100 is very, very quite.
At this point, I would suggest you consider a setup that gives you more flexible options. The Max4 and Max2 have the same mechanical "guts" as the Icemaster 100 except they have built in controllers and pumps. When you compare the price difference between the Icemaster 100 and the Max4, the Max4 costs $150 more. I suspect that covers the cost of the controllers and pumps.
While I understand the trend for some manufactures is to include controllers and pumps with their chillers, I personally do not like that permanent type of configuration. I like the ability to select what type of controller I want to use. Last December I bought Inkbird ITC-308 WIFI controllers when they were on sale for $25. They are great and have saved me so much money and time as I do not have to race home to adjust the temps. Since it is connected to my WIFI, I just pull out my iPhone and adjust the temps. The Max4 and Max2 as well as other manufactures controllers are NOT WIFI enabled!!! Btw, pumps are cheap too.
So, in the end I highly recommend the Icemaster 100 for its performance (can crash to 28F), for its quietness, and flexibility that allows one to choose their own controller that benefits their situation.