It has been well recorded and accepted that in the pantheon of dryness, for some unknown reason consumers regard dry as quality and sweet as not, granted these are not connosuiers that think in this way, however, rather it is those consumers that take a sip of the wine in order to test its quality, rather than sniffing it, in other words, pratts.
Many is the time that these fools must have sipped on a glass of Brut Nature only to have the lining stripped from the roof of their mouth while smiling and saying that they can taste the quality, quoting some hack "the quality is in the dryness".
For myself and most people with any sense of taste, a certain amount of sugar per gram is required in ones wine, in order to ensure that vomiting does not ensue after the first mouthful, to my own personal palate, a little only, but we all have different tastes, if for example your tastes veer towards the traditional then your champagne will be considerably sweeter, as 19th and 20th century champagnes go from demisec and up.
In the pantheon of quality champagnes, for some reason there are not very many high end extra brut, and at the top end only one that I know of. Presumably the reason for this is they are not particularly marketable, one would prefer something delicious when one spends £400 for a bottle.
The one top end Extra Brut is the Bollinger R.D. or Recently Disgorged, is both a vintage and a Extra brut, being produced in various different landmark years, in addition to which it is a unique concept within the world of fine champagnes, being both grande annee, and having been aged in the Bollinger cellars for up to 25 years.
1996 is accepted as the standard, however the finest is based around the 1952 vintage, with bottlings reaching the 10's of thousands.
And of course being an Extra Brut (and this is the other reason I love extra brut's) they can keep almost indefinetly before being opened and consumed.