Gotta jump in here Foxtrapper. Turning drums and rotors is a must if you are replacing pads / rotors. Your reply implies not to do so. Now if you meant only if the old pads / shoes were to be reused, you are right there unless there is a real distortion in the rotor / drum. Out of round is out of round and will give spongy brakes no matter what pads / shoes are used. If the rotors are vented style, not solid, then they are probably good for many turnings as long as the min thickness is not approached. Drums can be turned too, to nearly min thickness, especially if they are thicker, finned ones. One thing to look for on drums is the presence ( or lack of) welded on balancing weights. As drums are cast, they almost always have balancing weights welded on. These weights have been known to come off drums and cause all kinds of weird braking. Also, if the weight is pretty big, say bigger than a refrigerator magnet or two, chances are the drum is a poorly cast one and may be factory junk.

Anyway, old pads and shoes with little evidence of uneven wear, yeah, leave the rotor / shoe alone. If obvious uneven wear is there, something is wrong with the spring hardware or the caliper sliders / pad retainers or the rotor / drum itself.