Well,
I have shot about an equal number of weddings with TLR, then switched to Hasselblad.
I am always cognizant that I am a guest "in the house", so to speak. So, I make a point of talking to the clergy, and asking them "Hope I didn't interfere or make too much noise". I'm using a 500CM from the back, during the ceremony.
Interestingly, not ONE has ever said I was excessively noisy. The standard reaction (fifty weddings later) is, "I didn't even know you were back there". Good enuf.