I've tried the feature when I just got the truck, but had to turn it off pretty quickly. So, it went from "cool" to "ain't freaking worth it" within a few days.
I have a very similar crack on my 25 Lariat just four days after picking it up. It's about 12 inches form the very bottom in the middle of the windshield. Didn't hear/feel any rock hits or anything. The crack just appeared while the truck was sitting in the driveway for a couple of hours. Dealer...