It has no DI stage, and is more expensive than the unit that includes one when purchased from the right places over the internet. It does include the spigot and pressure tank, but you don't really need those. The cartridges on these units are proprietary, so when they need replacement, it'll be at Whirlpool's price.
You can get an RODI system over the internet for $150 shipped, that is exactly the correct unit.