I have been using the DX6i and only the DX6i for my Crawler. I love it!!! I use it because I fly Helicopters and Planes from the same radio. Makes it real easy to change from one to the next because it will hold up to 10 different models in the memory. I also bought my radio when they were giving away a free reciever for every reciver you bought!

I have 4WS set-up so I can flip a switch and have the rear steering turn automatically in the reverse direction. With the switch up, I can steer the front axles with the Aileron channel and the rear axles with the rudder. I am thinking about moving the rear independent steer to the elevator(would be weird to move the stick up and down) because I seem to lose throttle continuity if I try and steer with the rudder independently...Who knows, I might like just using the elevator to give the rear wheels the proper angles to make it up certain hits....Experimenting with it is the only way to know.

To set up the rear steer to move automatically you simply have to go into Mix1 in the submenu and set whatever channel your rear is on to move with the aileron. You can even give it a number value from 0-100 to assign how far the servo will travel while in rear steer mode. You then choose which switch you prefer for chosing between independent steering and auto 4WS. You also have to go to the reversing menu to assign the rear channel to turn opposite the front one....

You can ask me more questions and i will help you later if you actually buy this radio. The manual will tell you how to use Mix1-2 though...

Later!
Z