You are fortunate in that Minneapolis has very good water quality so even an ebay unit would suffice. Its when you get into challenging water situation that the research and development other vendors do really pays off. I used to own a Typhoon III which everyone raved about at the time. I could never get more than 150 gallons out of a DI cartridge no matter what I did. I even replaced the membrane and had Watts Premier bench test it for me and still 150 gallons before the TDS was at 2-3. I tried fresh resin from Resin Depot, AWI and many others and still the same.
I sold the unit and installed my first MaxCap. The very first DI went 830 measured gallons before it showed 1 TDS. The second and all subsequent cartridges have been over 1000 gallon since then. My MaxCap UHE is like 4 years old now, the membrane is the original still running at 99.43% efficiency, the tap TDS exceeds 560 to as high as 800, the RO only tDS runs between 2 and 3 using a handheld HM Digital COM-100 meter, and I have only replaced 1 MaxCap DI cartridge and 3 SilicaBuster DI cartridges in all that time. Thats with a 100G display/30G sump and a 16G nano.
As I keep pointing out, there really is a difference and my unit has already paid for itself in membrane and DI replacements as well as water and sewer savings.