Depending on the condition of the launch ramp or what I am pulling out of the water, I will use 2wd or 4wd auto. I have only had to use 4wd low once at Lake Tahoe where the launch ramp had "drifts" of soft sand under water. Couldn't get the boat out of the water in 2wd or auto.
It is pretty easy to leave the burb in 4wd so I use it in rare conditions only.