I have nothing but good things to say about Leupold Dual Dovetail. Solid and reliable lockup. You can't beat the Torx screw system either. I've been told that these screws are far less likely to strip out--when tightening or removing. I have Leupold bases and rings on my Remington 700. As most here will tell you, use the lowest rings possible for your gun. I wound up having to use the Medium rings because my bolt scraped the side of the scope with the Low rings.
The installation wrench made by Leupold is handy, though not necessary. In order to prevent marring the rings, you can simply pad the inside of an adjustable wrench (with some strips of cloth or foam) and then cover the padding with duct tape. Or you can use a one-inch wooden dowel to twist the rings into place. Whatever you do, don't lock in the rings using the scope. Far too much potential for bending the scope tube.