Apparently I am out numbered in this instance of sonar vs. camera debate!
He is not from Canada, he's proudly serving in the US military overseas and is attempting to order a truck before he returns to the states.
I have the camera and the lines. The lines are color coordinated to help assist in showing how close you are to an object. If you turn the wheel, the lines will also move and show the projected path of the vehicle. I love this feature and am not sure WHY it wouldn't be on every vehicle produced as it is that important of a feature. The sonar provided by the Park Assist just isn't something I have to have. The camera gives a decent view of the back of the truck so you'll know when you're getting close to something. I also have a fairly good idea of where the front of my truck sits and don't need the assistance of the sonar.
I do agree that for a $50k truck, it should have all the bells and whistles standard, but that's just not how it works in these newer trucks. I think we can all talk till we're blue in the face and the manufactures aren't going to change unless we just stop buying their products all together (which I enjoy their product too much to stop buying it)!
My garage space is tight and like most, I HAVE to park just right in order to make sure I am in the garage all the way. Since I don't have the park assist, I simply back into the garage and I have the spot marked where my rear bumper has to sit. Once I clear that mark on camera, I put it in park and enjoy the beauty of my awesome truck. My last truck had the sonar, but no camera. I would say that if you didn't have a camera, the sonar is a MUST, but since you've got the camera I just don't see a need for the sonar.