An extension of this question.
If I have a particular girsa of davening that I have always said (either because it is an established family or shul minhag, or because I have adopted it and done it a number of times) is this a statement that other girsa'ot are invalid as means of expression to fulfill an obligation? Is my minhag a rejection of all others inherently?
If my personal practice is (and I apologize if the example isn't the best) to say "v'shivchacha elokein" at the end of kedusha, am I saying that "ushvachaha" is wrong/unacceptable, so that if I say "ushvachacha" I have not said the bracha correctly? Or is another version equally valid and my minhag is a matter of choice among equals, so, ultimately, any version I choose allows me to fulfill my obligation, regardless of a minhag-preference?