So the growers in the estate Champagne (Growers) movement want to show off the quality of their production. Essentially what that means is the wines are "terroir-driven". Like all estate bottled wines, single barrel whiskeys, and assorted micro-brews; there is an "authentication/idiosyncracy of place" as the motivator for this production process. For Champagne makers, that usually means the product is a drier, brut nature-style which shows off terroir better than do the mega-producers' blends, which are often less dry.
The Champagne appellation, itself, is divided into alternative districts devoted to the two primary grapes of Champagne, Pinot Noir and Chardonnay. Montagne de Reims and Vallee de la Marne in the center of Champagne and just north of the Marne river are the best Pinot Noir districts. Just south of the river and south of Epernay lie the Cote des Blanc and Cote de Sezanne, the great Chardonnay districts. It makes sense for growers in these districts to market their wares through the Grower Champagne movement. In their optimal environs the pinots tend to accentuate the complexity of the Pinot Noir fruit while the Chardonnays show a crisp, pure minerality.
Eighty-eight percent of the vineyards of Champagne are independently owned; they number about 1,900 parcels total. There are seven categories of Champagne related to production arrangements. We have said that more than ninety percent of Champagne is made by the Maisons, the large negotiant houses. Less than three percent are Grower Champagnes. The other categories are hybrids, of sorts. Since villages are meeting places for growers; either the village, itself, may claim production or a co-operative within the village can effectively become the Champagne producer. Unions of growers can also produce as a unit. Private labels made by industry or restaurant/retail stores can also be labelled as producers. For identification purposes, all of these alternatives should be depicted on the Champagne label with two capital letters; examples include NM for "Negotiant Manipulant" or Maison and RM for "Recoltant Manipulant" in the case of Grower Champagne.
So going back to the main question about Grower Champagnes, are they better than the Maisons? Objectively, yes they are...and they are growing in number and popularity. And they don't have the advertising costs worked into the finished product price that the big guys have. Now here's a "be careful what you wish for" thought - could there be a "tipping point" in the future where the popularity of Grower Champagne could drive up prices to the point where the non-vintage Maisons become the better buy?