The reason for calibration software (discs) is that no 2 displays are identical. Other members settings may be close, but are not the best for your set. Other than the disc and your eyeballs, no other instrumentation is needed for a reasonably good calibration. Using quality instrumentation, or hiring a professional calibrator will get you the last 5% to 10% closer to perfection.
The biggest problem with calibration is psychological (your brain is easily fooled and hard to correct). Most people have never seen a well calibrated set (the ones in the stores are way off, because they sell sets that way). You have to do a calibration and use it for a week. You will discover that the picture actually looks more natural and realistic, once you get rid of the preconceived notions of what a good video display looks like.
Yes, you should use the HD DVD disc to tweak your set. You also want to get the THX Optimizer glasses (blue filter), so you can adjust the color (see
hwjohn's previous post, #636). The site is
www.thx.com/home/dvd/blueGlasses.html, per Google - but it is not responding right now (an alterate link is
www.thx.com/home/dvd/optimizer/index.html, but it is not responding either).