More expensive units may have multiple temperature zones, which is a nice feature if you want to keep your reds at one temperature and your whites at a cooler, more ready-to-drink temperature.
The units carry software that can fine-tune filtering in response to local changes in water temperature, salinity, pH and silt, and can be remotely controlled from a central operations center.
Control of ambient temperature is particularly critical when one apparatus is stacked above another, because the heat generated from the lower unit can interfere with the operation of the units above.