"These LTZs have some slight grooved tread within the treadblocks"

If I understand what you've described, it's called Siping (sp? - pronounced like pipe).

That gives you improved performance on dry pavement (I guess slick rock too). It won't help with anything else. They try not to use it too much though since it tends to make the tire wear faster.

Tom

BTW, your ride looks sweet with the new shoes.