My experience of Sunday morning is that dress in general has become more casual. To see a continuum ranging from jacket and tie to open collar and no jacket for men's dress on a typical Sunday is pretty much common practice. When I wear my kilt to church (and I do quite often), I like to wear a tie and waistcoat. I don't like to wear a belt and jacket as much. Sometimes I drop the tie and for very special occasions like Christmas and Easter, I'll wear a waistcoat and jacket (a black Argyle). I have found it more necessary to dress-down a little so as to fit the growing informality of Sunday morning. The neat thing a out the kilt is its versatility.