Can't speak for bank deals but when showing a house I have never dressed up "nicely" couple times in a jacket and jeans with nice shoes other times like a construction worker. Hoodie with paint and drywall compound all over it as well as pants. It has never effected the leasing of the property. Now when I go to a signing off the lease I ALWAYS dress up nice, it was a habit that I took up and it pays off I always get a compliment from it and the tenants usually know I mean business.
People will treat you differently depending on what you are wearing. It's like going to Lowes in a casual clothes, attendants will be all over you asking if you need help. But if you go in construction clothes and they don't ask you anything. Go into a business transaction in construction clothes and you may be looked at strange. But if you go in nice clothes you are treated as you know what you are doing.
What you are wearing is what people will judge you off of first.