I was practicing for my renewal on a G1000 equiped A/C a while ago. I used the GPS to overlay the tracks on the MFD through the use of the OBS mode. I had the ADF as my primary source. The NDB signal was quite bent, took me initially 10 degrees to the right of track before deciding to swing around putting me out of tolerance within a couple of seconds... I wouldn't be keen to fly the approach with an examiner anymore if its going to do that... will keep my recency flights to the sim.