In my experience the wines move right along in the cellar--perhaps because of the minimal sulfur. Have had '96 and '97 Les Perrieres in the past year and both we're very nice with mature flavors though still quite powerful.
Are the bottles coming from Breton's cave? If storage is at all questionable I would pass.
Had it in France last January and Joe is right, this is a wine to drink now, a little tired (at least based on that particular bottle I had but this was coming straight from Breton cellar).
Breton recently issued several vintages from its cellar, including the 1995 I had recently, and probably the various 1992, 1993, and 1994 vintages out there on the market.