I tend to buy a) what’s good¹, regardless of the initials in fine print on the label, and b) what is (reasonably) affordable; it also c) depends upon the occasion.
What that translates to is that I do have certain favorite producers, and it’s irrelevant to me whether they are NM, RM, CM, or RD’s . . . as long as I like what’s in the bottle – and it suits what I’m in the mood for (Blanc de Blancs, Brut Rosé, full bodied, light bodied, tête de cuvée, etc., etc.). So for example, my favorite Brut Rosé remains Billecart-Salmon (an “NM”), while my favorite Brut BdB is Pierre Peters (an “RM”).
But I see no reason whatsoever in spending the proverbial beaucoups bucks on fancy labels (think Jay-Z’s total bull$#|+ Armand de Brignac “Ace of Spades” Champagne) when there are umpteen labels which are better and less expensive . . .
OTOH, if the bottle is for someone else – as, say, a birthday present – the question becomes: will they appreciate the wine within the bottle, or would they be more impressed with the label? Even then, I’d stick with something like Moët & Chandon’s “Cuvée Dom Pérignon,” or Taittinger’s “Comte de Champagne” over anything so ridiculous as the “Ace of Spades”!
Now, one thing you may not know – or perhaps you do; I have no idea – is that, having spent most of my life in the wine trade, it’s probably reasonably safe to presume that I have tried any number of “Grower Champagnes” aka “Farmer’s Fizz” aka Récoltant-Manipulant (“RM’s”). I do not for a moment want to suggest that I’ve tried them all, or are familiar with all of them, but I’ve probably at some point tried a majority of those labels brought into the U.S.
Overall, it is true that I tend to buy more récoltant manipulant (grower) Champagnes than I do from the large producers (négociant manipulant).
¹ Though, I’ll confess “good” is an understatement; I find I have little patience for wines which are merely “good.”