Well, I am a Southerner too, but I don't have any pics of my son in dressy clothes. We don't dress like that normally, so my son just wouldn't look like himself.
My family is from Charleston, SC and my extended family is still there. I always find it interesting to go to church with my family back home (I'm in Florida) or out to a nice restaurant. Children get dressed up to go out somewhere nice (but then adults do too, but that is another story). Here in Florida, DS is one of only two boys that is ever "dressed" for church at the church we attend. He wears his sportcoat/shirt & tie/trousers during the fall and winter and sometimes just trousers and a nice sweater. During summer he wears pressed chinos, nubuck shoes or penny loafers and a pressed collared shirt. Shirts get tucked in, belt is on, and hair is combed (but this applies when he is going out in casual clothing too).
My friends always lament that they can't get their children to dress in nice dress clothing (especially boys) when they need to dress them for a funeral, wedding, pictures, Easter Sunday, etc. On the other hand my little man begged me for a new pair of penny loafers because his from last year no longer could be shined up much and he asked for a little boy tie in J Crew because it was black with tiny white skulls and cross bones and he wanted it for church.
I know most people have a casual lifestyle, but I think it is a shame very few people take an opportunity to get themselves and their children dressed up and do something special once and a while. I often see young professional adults struggle to pick out and look comfortable in a suit when they need to and I find it to be a little sad.
I look back at my parent's family pictures of them as children and we comment on the little starched embroidered dresses and little boys' dress clothing. I have a formal WW2 era picture of my dad (maybe 4 years old?) in pressed khakis with a leather bomber jacket and military like hat. I treasure these pictures. I would hate for my grandchildren to see nothing but pictures of my DS in jeans and other casual clothing. I still say it is nice to take both kind of pictures.
When my DS was about 2 my FIL bought him a cowboy hat. My son loved that cowboy hat so he would wear it everywhere and tell everyone that he was cowboy Joe. I took him to picture people with his cowboy boots jeans a flannel shirt and one of those stick riding horse things, and I think that is one of my favorite pictures of him. If you tell him now about Cowboy Joe he will deny it. So I agree to make it personalized, something just about him.
This is priceless! We have a similiar picture DS. I also just dressed him up and had the picture people take a picture in his elaborate halloween pirate costume. So we have Captain Kit and Farmer Kit, but we have nice dressy photos too.
Like I said, to each their own.