Since I got the Sinar F, and after looking at Tom Duffy's P2, which has asymmetric tilts and swings, I'm kind of liking these calculators (DOF and swing/tilt). They really do make certain kinds of things easier and quicker.
Since then, I've gotten the Rodenstock calculator and a Suunto Tandem clinometer-compass to try with my other cameras. The DOF calculator is fairly simple to use. The swing/tilt calculator requires that you know the angle of the plane of focus, which is why I started looking into a clinometer, and then I realized that if the camera doesn't have scales, you can use a clinometer and a compass to measure the tilt and swing angles, and generally to level the camera.
But back to the original post--look at Merklinger's website and particularly at the videos. Even though Merklinger's prose is dense, the videos are very clear. Stroebel is a handy reference.