..When the reviews rave how well the whole thing blends together and how a track from late 1970's flows to a track from early 2000. This on a 7x CD compilation of one man's career spanning over 30 years. I did the mastering.
I always keep on saying that mastering is at its best when you don't hear it. All you hear is the artist. If the review told that the mastering was well done, I'd felt like getting catched with my pants down.