My sharp aquos looked good as soon as i got it out of the box. About a month later, i decided to take the plunge and purchase this calibration dvd. After viewing the test patterns and using the color filters, i noticed a significant difference in how much better the color is. i didn't notice so much of a difference in the other settings as far as sharpness and contrast go. Even after setting the brightness with the dvd, i ended up bumping it up just a bit for daytime viewing.
I didn't get much out of the audio adjustments on my surround sound system. i got more out of the adjustments from simply using my receiver manual and remote.
In the end, after seeing other folks LCD tvs, i can tell mine has been adjusted properly with the test patterns. This was something i didn't notice until i saw someone elses tv and it was obvious the saturation needed to be adjusted.
All in all, it was a good investment. Not quite sure it was worth the $35 or so i paid for it, but my tv looks even that much better now that i have used it.