For the vintages you mentioned, 97 is excellent for cabernet in California, and quite consistent. 99 is a vintage I like for chardonnay, but individual regions can produce wide ranges of quality.
My favorite wines are French red burgundies, and the pinot noir grape is very susceptible to rot and to differences in the amount of sun or moisture/rain. Great vintages that I have tasted are 52, 53, 55, 59, 61, 64, 69, 71, 76, 78, 85, 90, 96 and 99. And I have had lousy wines from every single one of those vintages. But the relative quality and the consistency is what makes any one of those a fine vintage.
A wine from a great old vintage can be way over the hill, and a wine from a young vintage can be undeveloped, closed and harsh or thin. I have enjoyed many wines from lesser vintages that were perfect for drinking at the time the bottle was opened, and with the food we were eating. That's why a good sommelier can be trusted if he or she knows how a particular bottle is drinking now and how it matches up with the cuisine or dish of the restaurant.