Used properly, those dials are useful.
The tilt/swing calculator is very useful, as long as you place the plane of focus accurately. The situation you're describing where the near and far points are in focus, but not the middle ground is a common issue. Say you have an upward sloping landscape where you're in the valley looking toward the hills. Beginners usually imagine the plane of focus going from the ground under the tripod to the horizon at the ridgeline. Better to imagine the plane of focus going from the ground under the tripod to a line about 1/3 the distance below the ridgeline, so you don't "waste" the DOF above the plane of focus, which is in the shape of a wedge.
Now imagine another scene where you've got tall vertical structures, like trees, in the middle distance as well as mountains in the far distance. In this case, it might be better not to tilt and just use hyperfocal technique. This is where the DOF calculator comes in. It works as well as the DOF calculators on manual focus lenses for 35mm and MF cameras--if you're not making a big enlargement, you can use the recommended value, or if you like things a little sharper, you can stop down one or two stops from the recommended f:stop, which is what I usually do, considering whether I'm entering serious diffraction territory. Usually insufficient DOF is a bigger problem than loss of sharpness due to diffraction.