This is the best reason I can give!
Two nights ago it was almost dark and my wife called with a panicked voice saying she was stuck. The GPS for some reason told her to take a road to the RV park we were staying at. She said the road was fine then it turned to gravel then it turned to sand. She was stuck. I told her how to put it into 4wd. She tried to drive out but she was still stuck. I then told her how to go into 4low. She drove out with no effort and turned around drove to where she felt like she could drive in 2high. So just that experience made it worth every penny for her and me.