Hey Adam
Yep there are other 4WD controllers out there & compared to this unit they are all pretty basic. As a comparison, most other controllers only modify the signal in a linear way, meaning the 4WD responds exactly the same, just sooner (depending on the 1-10 setting) which this unit emulates in Map 1 (see below for how it does this).
If you take a look at the manual below on page 6 it will show you the comparison of 5 of the 8 available maps, with the solid black line being Map 1, the equivalent of most other controllers out there.
Not only does the Ruzic Engineering controller offer several curves for the response of the 4WD, it also has the ability to bring that response in earlier or later, depending on how the chassis responds & how much power the car is putting down. You can go from a very aggressive & fast-reacting torque split all the way back to predominantly RWD if so desired thru the ability to toggle between 2 map settings on-the-fly which makes it perfect for the Drags or anytime you may want the back of the car to get a bit loose & still have the ability to instantly go back to 4WD at the flick-of-a-switch
Ruzic Engineering 4WD Controller Manual