Your dealer wants to turn brake rotors at 2K miles??? Something is wrong with that story. You need brand new OEM replacement rotors and new brake pads too, if required due to defective rotors, under your warranty coverage.
However if GM and your dealer insist on turning brake rotors instead of replacement, you should first check out this informative video
http://www.oeqf.com/techinfo/scratch...atching_lg.htm; and then make sure that the lathe will grind a non-directional radial or concentric finish on your rotors rather than the typical directional spiral pattern (i.e., phonograph record groove) finish.
FWIW, my wife drove a '98 Catera (very nice!) for several years. A Cadillac dealer turned the brake rotors at 25K miles, and brake performance worsened exactly as described in the video (pulsing, clicking, longer stopping distances). Annoying and dangerous. Replaced brake pads, but no improvement. We got rid of the Catera shortly thereafter.